North Coast Redwoods District Trail Project

CALIFORNIA STATE PARKS TRAIL PROJECT SPECIFICATION DESCRIPTIONS

Trail Brushing Construction

This includes the removal of all brush within the travelway (2’ beyond the top of the cutbank to 2’ below the outboard hinge). The brushing limits will vary depending on the size of the deigned trail bed, percent of hillslope and the user group. Removal includes the stashing of cut brush off the travelway and out of sight. Any brush limbs projecting into the brushing limits will be severed at their axis and no stobs shall be permitted. Levels of brushing (light, medium, heavy and extra heavy) are based upon designed trail width and brush density. Unit of payment is by lineal foot. (Refer to trail brushing drawings in the specification diagrams.)

Trail Brushing Maintenance

Brushing maintenance is the removal of living or dead vegetation from within the brushing limits (1.5’ beyond the inboard and outboard hinges of the trail or 1.5’ beyond the outside edges of the trail bed on flat ground). Brushing maintenance removal limits are based on the trails classification and design standards.

Removal includes the stashing of cut brush off the travelway and out of sight. Any brush limbs projecting into the brushing limits will be severed at their axis and no stobs shall be permitted. Levels of brushing (light, medium and heavy) are based upon designed trail width and brush density. Unit of payment is by lineal foot. (Refer to trail brushing drawings in the specification diagrams.)

Clearing, Tree and Stobber Removal Construction

Removal of small trees, stumps of dead or felled trees and stobs of large brush within the travelway (2’ beyond the top of the cutbank to 2’ below the outboard hinge). Removal includes the root structure of the trees and brush and the stashing of all debris off the travelway out of sight. Any tree limbs projecting into the clearing limits will be severed at their axis and no stobs shall be permitted. Levels of clearing (light, medium, heavy and extra heavy) are based upon designed trail width, tree and stump density and tree size. Unit of payment is by lineal foot. (Refer to clearing and grubbing drawings in the specification diagrams.)

Down Tree Removal

The logging out and removal of trees lying across the intended travelway. Work includes the sawing out of down trees within the designed clearing limits and removing the sawn sections of tree out of the travelway (2’ beyond the top of the cutbank to 2’ below the outboard hinge). Sawn sections shall be stashed out of sight or placed perpendicular to the trail against the remaining sawn log. Unit of payment is based on the removal of each individual tree or log. Cost varies based on use of power tools or hand powered

saws and the diameter of the tree removed. (Refer to down tree logout drawings in the specification diagrams for clearing limits.)

Partial Stump Removal

This work involves the removal of large old growth stumps that are located in the intended travelway by using a chainsaw to cut out the desired tread dimensions. This includes removing the stump down to the approaching trail tread grade, providing a trail bed width to the prescribed specifications and laying back the remaining stump so it will not interfere with the intended trail users. All saw cuts shall be smooth and the saw curf shall be continuous. Multiple saw cuts with irregular surfaces will not be accepted. Sawn out sections shall be stashed out of sight. Unit of payment is based on the volume of cubic feet of stump removed.

Removal of Whole Tree by Rigging

This work involves using rigging techniques to remove large down trees from the intended travelway. Trees are to be removed/moved in such a fashion that saw cuts if required are not visible from the trail alignment. Final placement of down tree shall not inhibit natural sheet runoff flows or block drainages. Unit of payment is by number of crew hours required to remove each down tree.

Down Tree Removal Multiple Stem

The logging out and removal of trees lying across the intended travelway that have multiple stems. Work includes the sawing out of down trees within the designed clearing limits and removing the sawn sections of tree out of the travel way. Saw sections shall be stashed out of sight or placed perpendicular to the trail against the remaining sawn log. Unit of payment is based on the size and complexity of the tree removal. Cost varies based on use of power tools or hand powered saws. Unit of payment is by individual down tree removed. (Refer to down tree logout drawings in the specification diagrams for clearing limits.)

Trio Maintenance

This work includes removal of all organic debris from the trail bed, removal of sluff (soil and debris on the inboard hinge) and the soil berm on the outboard hinge of the trail. Mineral soil from the slough on the inboard hinge and the berm on the outboard hinge is used to fill depressions in the trail tread. This includes decompacting; reshaping and compacting the entire trail bed to achieve proper outslope and sheet drainage. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. It also includes brushing the travelway back to original construction standards. Levels of maintenance are based upon designed trail width. Unit of payment is by lineal foot. (Refer to trio maintenance drawings in the specification diagrams.)

Trio Maintenance Native Soil Accessible Trails

This work includes removal of all organic debris from the trail bed, removal of sluff (soil and debris on the inboard hinge) and the soil berm on the outboard hinge of the trail. The trail tread shall be re-cut to the original linear grade and cross slope standards by cutting into mineral soil. Filling of depressions or low areas with soil to achieve the required grades and cross slopes is prohibited. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted “firm and stable” and without holes, rock/root protrusions and concave depressions that can trap water. It also includes brushing the travelway back to original construction standards. Levels of maintenance are based upon designed trail width. Unit of payment is by lineal foot. (Refer to trio maintenance drawings in the specification diagrams.)

Trail Tread Construction Mechanized

Mechanized tread construction includes using hand crews to rake the duff and organics off the travelway to below the clearing limits. Using a trail dozer or mini excavator or both, the trail bed shall be excavated into the hillslope and be comprised solely of native soils (full bench) and no fill material shall be used to develop the trail bed. The equipment shall fully excavate the trail bed and lay the cutbank back to an angle where it is stable and remove or sidecast any soils forming a berm on the outside edge of the trail. The trail bed shall be cut to the proper width, linear grade and cross slope without using loose soils to fill low areas or depressions. The cross slope on trails with native tread shall at a minimum shall be 1.5 times the linear grade of the trail and may be increased as required by the contract representative. The finishing of the trail tread shall be performed by hand crews. This work also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Compaction shall consist of a minimum of two passes over the entire trail bed with a minimum 180 lb. plate compactor. Duff and organics below the clearing limits shall be lightly spread over the trail tread. Levels of construction are based upon designed trail width and the percent of hillslope. Unit of payment is in lineal feet. (Refer to trail reconstruction and reroute drawings in the specification diagrams).

Trail Tread Construction Hand Crew

3 concave depressions that can trap water. Compaction shall consist of a minimum of two passes over the entire trail bed with a minimum 180 lb. plate compactor. Duff and organics below the clearing limits shall be lightly spread over the trail tread. Levels of construction are based upon designed trail width and the percent of hillslope. Unit of payment is in lineal feet. (Refer to trail reconstruction and reroute drawings in the specification diagrams).

Trail Tread Construction Native Soil Accessible Trails

New tread construction includes raking duff and organics off the travelway to below the clearing limits. The trail bed shall be excavated into the hillslope and be comprised solely of native soils (full bench) and no fill material shall be used to develop the trail bed. The trail bed shall be cut to the proper width, linear grade and cross slope without using loose soils to fill low areas or depressions. The cross slope on trails with native tread shall not be less than 4% or exceed 4.5% unless specified by the contract representative. The cutbank shall be laid back to an angle where it is stable. This work also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Compaction shall consist of a minimum of three passes over the entire trail bed with a minimum 180 lb. plate compactor or until the tread meets “firm and stable” requirements. Duff and organics below the clearing limits shall be lightly spread over the trail tread. Levels of construction are based upon designed trail width and the percent of hillslope. Unit of payment is in lineal feet. (Refer to accessible trail reconstruction and reroute drawings in the specification diagrams).

Trail Reconstruction

Reconstruction of a trail includes removing vegetation and organics within the trail bed and raking duff and organics off the travelway to below the clearing limits, removing the outside berm, removing the slough on the inboard hinge, laying back the cutbank back to an angle where it is stable, fully re-cutting the trail bed to establish a full bench to the desired trail width, linear grade and cross slope. The cross slope on trails with native tread shall at a minimum 1.5 times the linear grade of the trail and may be increased as required by the contract representative. It also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Compaction shall consist of a minimum of two passes over the entire trail bed with a minimum 180 lb. plate compactor. Duff and organics below the clearing limits shall be lightly spread over the trail tread. Levels of reconstruction are based upon the use of mechanized equipment or hand crew labor to perform the reshaping of the trail prism and the designed trail width. Unit of payment is in lineal feet. (Refer to trail reconstruction and reroute drawings in the specification diagrams).

Trail Reconstruction Native Soil Accessible Trails

Reconstruction of a trail includes removing vegetation and organics within the trail bed and raking duff and organics off the travelway to below the clearing limits, removing the outside berm, removing the slough on the inboard hinge, laying back the cutbank back to an angle where it is stable, fully re-cutting the trail bed to establish a full bench to the desired trail width and linear grade. The cross slope on trails with native tread shall not be less than 4% or exceed 4.5% unless specified by the contract representative. It also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Compaction shall consist of a minimum of three passes over the entire trail bed with a minimum 180 lb. plate compactor or until the tread meets “firm and stable” requirements. Duff and organics below the clearing limits shall be lightly spread over the trail tread. Levels of reconstruction are based upon the use of mechanized equipment or hand crew labor to perform the reshaping of the trail prism and the designed trail width. (Refer to accessible trail reconstruction and reroute drawings in the specification diagrams).

Trail Hardening Aggregate

Deformities on the pre-existing tread surface shall be corrected before installing the aggregate material. If the trail is entrenched or has excessive berms, remove the berm and correct the drainage first (this work should be included under trio maintenance or trail reconstruction). On existing trails, the trail tread shall be scarified to allow the native soils to bond with the aggregate. On new trails the trail tread shall be fully cut and shaped but not compacted. If specified by the contract representative, a layer of non woven geotextile fabric shall be laid down to support the aggregate material. Starting from the nearest point to the aggregate material source, install a lift of crushed aggregate a maximum of three inches thick. This lift shall extend to the furthest end of the hardening application. On outsloped trails the aggregate shall be placed up against the cutbank to facilitate sheet flow. Shape and compact the first lift to the specified linear grade and cross slope. Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. The second lift (maximum of 3”) shall begin at the furthest end of the hardening application and be installed back towards the material source. Apply the crushed aggregate to the specified finished depth, shaping it carefully as with the first lift to ensure proper drainage. An additional lift (if required) would be installed in the same fashion. When applying crushed aggregate, if specified by the contract’s representative, mix in native soils (a minimum of one inch in depth) into this top layer before compacting. The final surface is outsloped or crowned and compacted to the percent of slope determined by the contract’s representative. Compact the full width of the trail to the finish grade designated by the contract’s representative using a minimum of four passes over the entire trail bed with a 180 lb. plate compactor. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Levels of construction vary by mode of aggregate transportation and distance from trailhead. Unit of payment is

5 based on cubic feet of trail hardened with aggregate. (Refer to trail hardening with aggregate drawings in the specification diagrams.)

Trail Hardening Aggregate Accessible Trails

The cross slope on trails with native tread shall not be less than 4% or exceed 4.5% unless specified by the contract representative. Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. The second lift (maximum of 3”) shall begin at the furthest end of the hardening application and be installed back towards the material source. Apply the crushed aggregate to the specified finished depth, shaping it carefully as with the first lift to ensure proper linear grade and cross slope. Additional lifts (if required) would be installed in the same fashion. When applying crushed aggregate, if specified by the contract’s representative, mix in native soils (a minimum of one inch in depth) into this top layer before compacting. The cross slope (outslope) on tread’s final surface shall not be less than 4% or exceed 4.5% unless specified by the contract representative. Compact the full width of the trail tread using a minimum of four passes over the entire trail bed with a 180 lb. plate compactor or until the tread meets “firm and stable” requirements. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Levels of construction vary by mode of aggregate transportation and distance from trailhead. Unit of payment is based on cubic feet of trail hardened with aggregate. (Refer to trail hardening with aggregate drawings in the specification diagrams.)

Trail Hardening Stone Pitching

Rocks used in stone pitching structures must have sufficient mass to retain their position and support the intended used traffic. For pedestrian and mountain bike traffic rocks should be a minimum of 300 to 400 lbs. For equestrian traffic they should be a minimum of 400 to 500 lbs. To install stone pitching a footing is excavated into the trail bed that is wide enough to produce the desired tread width and long enough to correct the condition requiring this structure. The depth of the footing will vary. If the structure is elevated above the surround soil horizons it must be deep enough that a minimum of one third of the rocks mass is below grade. If the top of the structure is even with the surrounding soil horizons then the depth is equal to the height of the rocks used. If the

6 stone pitching is used where the underlying soil is weak and chronically wet a layer of non- woven geotextile fabric is placed at the bottom of the footing. Once the excavation is completed, the stones can be placed. The initial stones are laid at the lowest point of the structure. These key stones should be the largest stones within the structure. If possible these stones should be anchored or locked into existing bedrock that further key in the structure. The key stones must be well secured as they will serve as a buttress for the rest of the structure. Since the top of the stone will serve as the trail tread it should be relatively flat and uniform.

The sides of the stone need to have a shape that makes good contact with the stones placed next to it. The bottom of the stone can have an irregular surface as it will be in the bottom of the footing and the soil can be excavated to adjust to the shape of the stone. The stones are placed so that their tops or surfaces are at the desired tread elevation. To achieve this elevation it may be necessary to further excavate into the foundation bed or to place crushed rock underneath the stone to raise it to the desired elevation. The next stones are selected and placed to achieve a tight fit against the previous. Stone shaping tools such as hand chisels, hand points and spauling hammers may be required to obtain a close fit between the rocks. The gap between these rocks should be a maximum of ½ inch. The surface of the rocks should match each other and conform to the designed trail grade. Once all the stones are laid in this fashion it may be necessary to drive rock wedges along the outside edge of the structure to fill any voids and further tighten the rocks against each other. The final step in installing the stone pitching structure is to chink the spaces between the rocks at their surface. This is performed by pounding pieces of crushed rock into the voids between the rocks until the surface of the structure is relatively uniform and smooth. Unit of payment is based on cubic feet of trail hardened with rock. (Refer to trail hardening with stone pitching drawings in the specification diagrams.)

Trail Hardening Rip Rap

In constructing rip rap, the entire section of trail being hardened shall be excavated to the designed tread width and to a minimum depth of 12”. Any bedrock or deeply seated boulders encountered during the excavation shall be incorporated into the rip rap and used as key stones. The placement of the rip rap shall begin at the lowest end of the trail. The first rocks set shall be the largest as they will server as key stones. Rocks shall be placed with the narrow side facing up. The rocks shall be a minimum of 12” in height and a maximum of 8” in width. The exposed rock surface shall be at trail grade and be relatively flat but have a rough and irregular surface. Rocks shall be laid in tiers or courses, working evenly from the bottom up. Each rock shall be laid so that its top surface roughly follows the designed trail gradient. It is important to maintain as uniform a rise as possible throughout the rip rap run. All joints shall be broken. Rocks shall be laid tightly together with good contact on all sides. The top of the rocks shall achieve their designed elevation by either digging deeper into the trail bed with tall rocks or by installing tightly compacted crushed rock underneath them with short rocks. The rip rap surface shall have maximum ½” gaps between them. Once all the rock is laid, all gaps shall be chinked by driving rock spalls into them. Any gaps or voids along the perimeter of the structure shall also be chinked with rock spalls

7 to tighten the structure. Unit of payment is based on cubic feet of trail hardened with rock. (Refer to trail hardening with rip rap drawings in the specification diagrams.)

Trail Hardening Stabilizer Accessible Trails

Deformities on the pre-existing tread surface shall be corrected before installing the stabilized material. If the trail is entrenched or has excessive berms, remove the berm and correct the drainage first (this work should be included under trio maintenance or trail reconstruction). On existing trails, the trail tread shall be scarified to allow the native soils to bond with the stabilizer material. On new trails the trail tread shall be fully cut and shaped but not compacted. If specified by the contract representative, a layer of non woven geotextile fabric shall be laid down to support the aggregate material. Following the manufacture’s recommendations the stabilizing material shall be thoroughly mixed (batched) with the soil or aggregate material specified at the trailhead or access point.

Starting from the furthest point of the trail to eliminate the need to haul over freshly placed stabilizer, install a lift of stabilized material a maximum of three inches thick. This lift shall extend to back to the beginning of the trail. On outsloped trails the aggregate shall be placed up against the cutbank to facilitate sheet flow. Shape and compact the lift to the desired linear grade. The cross slope (outslope) shall not be less than 4% or exceed 4.5% unless specified by the contract representative. Compaction shall consist of a minimum of four passes over the entire trail bed with a 180 lb. plate compactor or until the tread meets “firm and stable” requirements. Additional lifts (if required) shall be installed in the same manner. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water.

Levels of construction vary by mode of stabilizer transportation and distance from trailhead. Unit of payment is based on square feet of trail stabilizer installed. (Refer to trail hardening with aggregate “accessible trail drawings” in the specification diagrams.)

Trail Hardening Asphalt Contract with Paving Machine & Hand Crew Application Accessible Trails

Prior to installing the asphalt, a 3” layer of crushed aggregate (separate cost item) shall be installed as per the aggregate surfacing specification. If specified by the contract representative, a layer of non-woven geotextile fabric shall be laid down to support the aggregate material. When purchasing asphalt, the following specifications shall be used: 1. Asphalt concrete must be produced in a central mixing plant and conform to Section 39-3 of the California Department of Transportation Standard Specifications. 2. Aggregates must conform to the half-inch maximum, medium grading, Type B, specified in Section 39-2.02 of the Standard Specifications mentioned in (1) above. 3. Asphalt binder must be AR-2000 to AR-8000 steam-refined asphalt, conforming to Section 92, Standard Specifications.

4. The amount of binder to be mixed with the aggregate should be between four and seven percent by weight of the dry aggregate.

When installing asphalt the following specifications shall be followed: Applying Tack Coat 1. Rate of application is between 0.02 and 0.10 gallons per square yard 2. Tack coat is applied at a temperature between 75 degrees F and 130 degrees F. 3. Do not apply tack coat when it is wet or rain is imminent, the atmospheric temperature is below 50 degrees F and falling, or the pavement or base materials are below 50 degrees F and falling.

Laying Asphalt 1. Paving operations begin at the furthest point of the trail to eliminate the need to haul over freshly placed asphalt. 2. Apply asphalt deep enough to produce the planned thickness after compaction (generally 1/4" compaction per inch of asphalt). 3. Spread asphalt so that no separating of coarse and fine aggregate occurs (rising of larger aggregate to the surface). 4. Lumps of hardened asphalt are raked out and discarded. 5. When conforming to existing surfaces, the asphalt is feathered to achieve the correct transition between surfaces. 6. When the asphalt is put down in two or more applications, the joints receive a tack coat and are lapped and not butted together. 7. The finished surface must provide adequate drainage and sheeting of water. On outsloped trails the aggregate shall be placed up against the cutbank to facilitate sheet flow. Install the asphalt to the desired linear grade. The cross slope shall not be less than 4% or exceed 4.5% unless specified by the contract representative.

Compacting Asphalt 1. Initial rolling is completed before the asphalt's temperature is below 200 degrees F. 2. The rolling is performed so that cracking, shoving, or displacement does not occur. 3. A minimum of three complete rollings are performed after the initial rolling. 4. The final rolling is completed before the asphalt temperature is less than 150 degrees F. 5. The completed surfacing must be thoroughly compacted, smooth and free from ruts, humps, depressions, or irregularities.

Unit of payment is based on square feet of asphalt installed. (Refer to trail hardening “accessible trail drawings” in the specification diagrams.)

Hardening GeoBlock One 6.5’ Wide Panel

Prior to installing GeoBlock on new trails, the travelway shall be cleared of all trees, shrubs, rocks and large roots. Tussocks and thick clumps of grass shall be cut or cleared to ground level. On existing trails the travelway shall be brushed and the irregularities in the trail bed corrected to the extent practical. The trail bed (cross slope) should be as level as practical. This work is covered under brushing, clearing, trail tread construction or trail tread reconstruction categories. If specified by the contract’s representative a layer of non woven geotextile fabric shall be installed prior to the installation of the GeoBlock panels. To make the assembly of the GeoBlock manageable, they shall be pre assembled in subsections adjacent to the trail hardening section (six panels for a 6.5 foot wide trail). All GeoBlock subsections are assembled top surface down. The panels shall be laid out in a staggered (bricklaying) pattern to minimize continuous joints. They shall be fastened together using the perimeter interlocking tabs and thread forming tapping screws provided by the GeoBlock manufacture. A minimum of two tabs shall be used to fasten each exterior joint between panels. Along the interior joints, a minimum of two tabs shall be fastened every 6 inches of the panel’s length. Additional wire ties shall also be used to fasten the panels together. All subsections shall be assembled using the same pattern. Once all subsections are assembled, they shall be fastened together in sections of three subsections each (minimum) using the perimeter interlocking tabs, thread forming tapping screws and wire ties. They shall be assembled using the same repetitive pattern to minimize continuous joints and increase panel strength.

These three unit sections shall then be moved to the trail bed and assembled together following the same pattern. Once all the three section panels are fastened together the GeoBlock cells shall be filled with soil or aggregate as specified by the contract’s representative. The fill material shall be shaped to provide a crowned surface with minimum outslope of 12%. Compaction of the fill material shall consist of a minimum of three passes over the entire trail bed with a 180 lb. plate compactor. If the GeoBlock cells are not filled with rock or soil, is not shaded by vegetation and is installed in sections longer than 40 feet then expansion sections shall be installed a minimum of three (three section panel) or every 40 feet. Expansion sections shall consist of SolGrid panels. The Geoblock and SolGrid panels shall be fastened together through the use of self-taping screws and wire ties. . Unit of payment is by square feet of GeoBlock Installed. (Refer to GeoBlock installation drawings in the specification diagrams.)

Hardening GeoBlock Two 1.7’ Wide Panels

installation of the GeoBlock panels. To make the assembly of the GeoBlock manageable, they shall be pre assembled in subsections adjacent to the trail hardening section (12 panels for each 1.7 foot wide tread strip). All GeoBlock subsections are assembled top surface down.

They shall be fastened together using the perimeter interlocking tabs and thread forming tapping screws provided by the GeoBlock manufacture. Additional wire ties shall also be used to fasten the panels together. A minimum of two tabs shall be used to fasten each exterior joint between panels. Once all subsections are assembled, these three unit sections shall then be flipped over onto the trail bed and fastened together using the perimeter interlocking tabs, thread forming tapping screws and wire ties. Once all the subsection panels are fastened together the GeoBlock cells shall be filled with soil or aggregate as specified by the contract’s representative. The fill material shall be shaped to provide a crowned surface with minimum outslope of 12%. Compaction of the fill material shall consist of a minimum of three passes over the entire trail bed with a 180 lb. plate compactor. If the GeoBlock cells are not filled with rock or soil, is not shaded by vegetation and is installed in sections longer than 40 feet then expansion sections shall be installed a minimum of three (three section panel) or every 40 feet. Expansion sections shall consist of SolGrid panels. The Geoblock and SolGrid panels shall be fastened together through the use of self taping screws and wire ties. Unit of payment is by square feet of GeoBlock Installed. (Refer to GeoBlock installation drawings in the specification diagrams.)

Site Restoration for Trail Obliteration and Narrowing Level Ground

Work includes loosening and aerating compacted trail tread soils and planting prescribed native vegetation in random patterns, placing woody debris on old trail alignment in a random fashion consistent with native debris density, placing duff and forest organic material on top of all disturbed areas at a rate consistent with the surrounding forest. Unit of payment is based on the use of mechanized equipment or hand crew labor to perform the de-compaction of the trail bed and by square feet of trail obliterated. (Refer to trail rehabilitation drawing in the specification diagrams.)

Site Restoration for Trail Removal (Full Fill Recovery)

Work includes removal of organics on trail prism, loosening and aerating compacted trail tread soils, pulling the fillslope or original sidecast soils below the outboard hinge up against the cutbank and reshaping the trail bed to original pre trail contours, planting prescribed native vegetation in random patterns, placing woody debris on old trail alignment in a random fashion consistent with native debris density, placing duff and forest organic material on top of all disturbed areas at a rate consistent with the surrounding forest. Unit of payment is based on the use of mechanized equipment or hand crew labor to perform the de- compaction of the trail bed and recontouring of the trail prism and by linear feet of trail restored/removed. Cost varies depending on the percent of hillslope the width of the trail bed removed. (Refer to trail rehabilitation drawing in the specification diagrams.)

Site Restoration for Bridges, Handrails, Wood Steps, Wood Retaining Walls, Rock Waterbars, Rock Retaining Walls & Wood Railing Fences

Work includes the complete disassembly and removal of the trail structure. This includes removal of all metal fasteners and pinning. Any holes or depressions in the earth left from the removal of the structure shall be filled with native soils and graded to the surrounding ground elevations. Structures are to be broken down into packable components and carried to the trailhead and loaded into a vehicle supplied by the contract’s representative or contractor, or are burned onsite at a location and in a manner prescribed by the contract’s representative. Any additional site restoration shall be treated as trail obliteration and reimbursed under that category of work. Unit of payment is lineal feet for bridges, hand railing, wood railing fences and culverts, square feet for wood retaining walls, cubic feet for rock waterbars, steps and retaining walls and each for wood steps and waterbars, trestles and signs.

Site Restoration Asphalt Removal

Work includes breaking up existing asphalt surfacing material into manageable chunks, loading it into wheelbarrows, stretchers or motorized toters and transporting it to a location near the trailhead designated by the state’s representative. All asphalt materials (even small granules) shall be removed from the prescribed worksite. Any asphalt materials that are spilled during transit to the trailhead shall be cleaned up and transported to the designated location. Cost of removal varies by use of mechanized equipment or hand labor to break up and load asphalt, use of wheelbarrows, use and size of toters and distance from trailhead. Unit of payment is by square feet of asphalt surface removed.

Site Restoration Soil Stabilizer Removal

Work includes breaking up existing soil stabilizer surfacing material into manageable chunks, loading it into wheelbarrows, stretchers or motorized toters and transporting it to a location near the trailhead designated by the state’s representative. All stabilizer materials (even small granules) shall be removed from the prescribed worksite. Any stabilizer materials that are spilled during transit to the trailhead shall be cleaned up and transported to the designated location. Cost of removal varies by use of mechanized equipment or hand labor to break up and load stabilizer, use of wheelbarrows, use and size of toters and distance from trailhead. Unit of payment is by square feet of soil stabilizer surface removed.

Switchback Construction

The construction of a switchback includes the excavation of the designed trail bed, upper leg transition, upper leg drainage, corner drainage, turn, turn transition and lower leg drainage. Construction of required retaining structures will be additional work under retaining wall construction. It also includes shaping and compacting the trails tread, cutbank and fill slope. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Levels of construction are based on the use of mechanized equipment or hand crew labor, the designed tread width and percent of

hillslope. Unit of payment is by each structure. (Refer to switchback construction drawings in the specification diagrams).

Climbing Turn Construction

The construction of climbing turns includes the excavation of the designed trail bed, upper leg transition, upper leg drainage, corner drainage, turn, turn transition and lower leg drainage. Construction of required retaining structures will be additional work under retaining wall construction. It also includes shaping and compacting the trail tread, cutbank and fill slope. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Levels of construction are based on the use of mechanized equipment or hand crew labor, the designed tread width and percent of hillslope. Unit of payment is by each structure. (Refer to climbing turn construction drawings in the specification diagrams).

Switchback Reconstruction

The reconstruction of a switchback includes re-establishment of the designed trail bed, upper leg transition, upper leg drainage, corner drainage, turn, turn transition and lower leg drainage. Reconstruction of required retaining structures will be additional work under retaining wall construction. It also includes reshaping and compacting the trail’s tread, cutbank and fill slope. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Levels of reconstruction are based on the use of mechanized equipment or hand crew labor and the designed tread width. Unit of payment is by each structure. (Refer to switchback construction drawings in the specification diagrams).

Climbing Turn Reconstruction

The construction of climbing turns includes re-establishment of the designed trail bed, upper leg transition, upper leg drainage, corner drainage, turn, turn transition and lower leg drainage. Reconstruction of required retaining structures will be additional work under retaining wall construction. It also includes reshaping and compacting the trail’s tread, cutbank and fill slope. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Levels of reconstruction are based on the use of mechanized equipment or hand crew labor and the designed tread width. Unit of payment is by each structure. (Refer to climbing turn construction drawings in the specification diagrams).

Barrier Log Construction

A footing or trench shall be excavated to contain the log. The trench shall be large enough to fully support and secure the log being placed into it. The depth of the trench shall be a minimum of one third of the height or diameter of the log being placed into it. The bottom of the trench shall be shaped to accommodate any of the irregular shapes

13 associated with the log. Logs are placed into the trench and secured by pinning them with rebar. The holes for the rebar (a minimum of two per log) are drilled prior to setting the logs in the trench. The diameter of the hole shall be 1/16 of an inch less than the 5/8” rebar used in pinning the log. The rebar shall be long enough to penetrate a minimum of 2’ into the ground beyond the bottom of the log. The top of the logs shall project a minimum of 1.5’ above the outside edge of the trail tread to prohibit cutting between the legs of the turn. Once the log is pinned the back of the wall shall be backfilled with the desired trail tread material and shaped and compacted. Unit of payment is based on the distance the log is moved and square foot of log placed. (Refer to barrier log drawings in specification diagrams.)

Rock Barrier Construction A footing or trench shall be excavated below the upper leg of the turn to contain the rocks. The depth of the trench shall be a minimum of one third of the height of the rocks being placed into it. The bottom of the trench shall be shaped to accommodate any of the irregular shapes associated with the rocks and be tilted back into the hillslope a minimum of 5%. Rocks shall be placed in the trench starting at the lowest point of the trench. The largest rock shall be installed first as it serves as a keystone that buttresses the rest of the rocks in the trench. All the rocks shall be placed so that their mass is on the inboard side of the trench (into the hillslope). The top of the rocks shall project a minimum of 1.5’ above the outside edge of the trail tread to prohibit cutting between the legs of the turn. The sides of the rock shall be placed or shaped so that they make good contact with the rock next to it. The back of the wall shall be backfilled with a combination of crushed rock and soil and compacted in maximum 6 inch lifts. Unit of payment is based on the distance the rocks are moved and the cubic feet of rock barrier constructed. (Refer to rock barrier drawings in specification diagrams.)

Wall Less Turnpike Construction Imported Material

Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. The second 3” lift shall begin at the furthest end of the turnpike and be installed back towards the material source. Apply crushed aggregate or mineral soil to the specified finished depth, shaping it carefully as with the first lift to ensure proper drainage. When applying crushed aggregate, if specified by the contract’s representative, mix in native soils to this top layer before compacting. The final surface is compacted and crowned with a minimum 12% slope to prevent water from

accumulating on the trail. Compact the full width of the trail to the finish grade designated by the contract’s representative using a minimum of four passes over the entire trail bed with a 180 lb. plate compactor.

Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Levels of construction vary by distance from trailhead, method of material transportation and accessibility. Unit of payment is based on cubic feet of turnpike constructed. (Refer wall less turnpike drawings in the specification diagrams.)

Wall Less Turnpike Construction Native Soils & Parallel Ditches

Deformities on the pre-existing tread surface shall be corrected before installing the turnpike material. If the trail is entrenched or has excessive berms, remove the berm and correct the drainage first (this work should be included under trio maintenance or trail reconstruction). On existing trails, the trail tread shall be scarified to allow the native soils to bond with the turnpike material. On new trails the trail tread shall be fully cut and shaped but not compacted. If specified by the contract’s representative, a layer of non woven geotextile fabric shall be laid down to support the turnpike material. To generate the soil for the turnpike, two parallel ditches shall be dug (one on each side of the trail tread). All vegetation and organics shall be removed prior to excavating the ditches. The excavation of the ditches shall not encroach into the designed trail bed or in any way undermine or destabilize it. The material excavated when constructing the ditches shall be used to elevate the trail tread. Once the ditches have been excavated to the proper depth and width the banks of the ditches shall be laid back to the angle where they are stable. The slope of the ditches shall be equal to the trail grade. When approaching a cross drain structure, the ditches grade shall gradually increase in order to obtain the elevation of the cross drain. Soil from the ditches shall be installed in maximum 3 inch lifts. After each lift the trail tread shall be properly shaped and compacted. Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor.

The final surface is compacted and crowned with a minimum 12% slope to prevent water from accumulating on the trail. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Levels of construction vary by tread width. Unit of payment is based on lineal feet of turnpike constructed. (Refer wall less turnpike drawings in the specification diagrams.)

Log Turnpike Wall Construction

When installing logs, a trench shall be excavated to provide a bed or footing for the log. In addition, these logs shall be tied together with heavy nine gauge galvanized wire to prevent them from spreading. If more than one length of log is required to frame in the turnpike the logs shall be joined together with a lap joint. The joint shall be drilled and pinned with a length of rebar 5/8”. The rebar shall penetrate a minimum of 2’ into native ground. If specified by the contract’s representative, a layer of non woven geotextile fabric can be laid down between the logs to help support the fill material if the parent soils are

too weak. The backfill shall be comprised of rock or mineral soil as specified by the contract’s representative. This material shall be placed and compacted in lifts. Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. These lifts shall not exceed 3” in depth. The final surface is compacted and crowned with a minimum 12% slope to prevent water from accumulating on the trail. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Levels of construction of log retaining walls vary by distance logs moved. Unit of payment is by square foot of logs placed. Payment for installation of turnpike material is a separate item covered under Wall Less turnpike or aggregate surfacing construction imported material. (Refer to log turnpike drawings in the specification diagrams.)

Causeway Rock Wall Construction

Causeway walls shall be laid into a footing dug into mineral soil a minimum depth of 1/3 of the wall rock height. Rocks shall be laid so the most uniform surface is facing towards the outside of the wall. If the causeway is being installed on an accessible trail the inside of the rock must be nearly vertical to provide a uniform depth of turnpike material. Rocks shall be placed to be stable, uniformly level and have good contact between the adjoining faces especially near the top. The inside of the causeway shall be filled with crushed rock or aggregate and geotextile fabric may be used as an underlayment if specified by the contract’s representative. The causeway shall be filled to within no more than 6 inches from the top of the walls with rock no more than 4 inches in diameter. An additional layer of geotextile fabric may be installed on top the crushed rock if specified by the contract’s representative. The crushed rock shall then be topped with mineral soil to create the trail tread. The final surface is compacted and crowned with a minimum 12% slope to prevent water from accumulating on the trail. Compaction shall consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. Finished trail tread shall be uniformly smooth, compacted and without holes and concave depressions that can trap water. Unit of payment for rock retaining walls is by cubic foot of single tier rock wall placed. Payment for installation of turnpike material is a separate item covered under Wall Less turnpike, aggregate surfacing construction or rock import. (Refer to causeway drawings in the specification diagrams.)

Drain Lens Construction

A trench shall be excavated below the trail tread to a depth specified by the contract’s representative. The bottom of the trench shall be cover with a layer of non woven geotextile fabric. On top of the fabric angular 6” to 8” diameter rock shall be placed point to point to allow for adequate spacing between rocks. The layer of angular rock shall have a minimum depth of 12”. The outside edge of the angular rock shall extend beyond the designed tread width at a maximum slope of 1 to 1. The top of the 6” to 8” rock shall be covered by a layer of woven geotextile fabric. A final layer of crushed rock or mineral soil shall be placed on top of the fabric a minimum depth of 6”. This material shall be installed at a uniform depth and shall extend a minimum of 6” beyond the fabric margins. This material shall be uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Compaction shall

consist of a minimum of two passes over the entire trail bed with a 180 lb. plate compactor. The final tread elevation shall match the approaching trail grades. Unit of payment is based on cubic feet of rock lens. (Refer to drain lens construction drawings in the specification diagrams.)

Culvert Installation

Culverts shall be installed by removing the vegetation that will be within the excavation limits. This clearing shall extend a minimum of two feet beyond the inlet and outlet of the culvert. Sediment control devices such as silt fences or straw waddles shall be installed downslope of the intended excavation area to prevent sediment from entering the watershed. If the stream is running, a small coffer dam shall be installed above the excavation limits to capture the stream flow. The water shall be diverted around the excavation area and back into the stream below the worksite through flexible plastic pipe. All excavated material shall be exported to a stable location far enough away from the crossing site that it cannot re-enter the crossing. Additional silt fences shall be installed between the crossing and the excavated material. The culvert trench excavation begins at the bottom of the crossing. The culvert trench shall be excavated so that the bottom of the trench is the same as the stream’s natural gradient and alignment. The bottom of the culvert trench shall be uniformly smooth, well compacted and comprised of soils that are free of large or sharp rocks and roots or woody debris. The culvert is placed into the trench. Prior to backfilling the culvert trench, headwalls shall be installed at the culvert inlet and outlet. The culvert shall be backfilled with soil free of large or sharp rocks or wood that could puncture or deform the culvert or interfere with the backfill material forming a tight seal around the culvert. The backfill material shall be placed and compacted in maximum 6” lifts if a mechanical compactor is used or 3” lifts if compaction is achieved with hand tools. The backfill material is installed in the required lifts until it covers the top of the culvert a minimum of 4”. At final grade the culvert shall have a minimum of 8” of soil covering it. The culvert crossing when completed shall pull up into the drainage and then dip down to the center of the culvert and then climb or rise out of the crossing. In situations where a new culvert discharges onto an unstable stream channel, an energy dissipater shall be required at the outlet. The energy dissipater shall be constructed into the streambed so that the top center of the dissipater is at stream gradient. The energy dissipater shall have a concave cross section and not displace the active stream channel. Unit of payment is based on lineal feet of culvert installed and the diameter of the culvert installed. Payment for headwalls and energy dissipaters installed is covered separately under those items. (Refer to culvert installation drawings in specification diagrams.)

Rock Culvert Headwall Construction

When installing a rock headwall the first tier shall be laid under the bottom of the culvert so that the bottom of the culvert sits flush on the top of the first tier of rock. To achieve this, the first tier of rocks must be set into a trench that is excavated below the natural stream channel grade. This trench extends into the adjacent stream banks a minimum of 1’. The front of the headwall shall protrude a minimum of one (1) inch beyond the ends of the culvert pipe. The second tier shall be laid in the same fashion as a multi-tier

rock wall except that the rocks butting up against the outside culvert wall are selected or shaped to conform to the shape of the culvert. The ends of the headwalls shall be terminated into the adjacent streambank so that the stream flow cannot flank and erode the headwall. The shape of the inlet headwall shall be similar to a broad funnel. The outlet headwall shall be shaped so that it is perpendicular to the stream flow. The top of the headwalls shall be a minimum of six inches above the top of the culvert. Unit of payment is based on cubic feet of rock installed. (Refer to rock culvert headwall installation drawings in specification diagrams.)

Energy Dissipater Construction

The energy dissipater shall be constructed into the streambed so that the top center of the dissipater is at stream gradient. Stones used for the energy dissipater shall be a minimum of 1cubic foot in size for smaller drainages and 2 cubic foot in size for larger drainages. The energy dissipater shall have a concave cross section and not displace the active stream channel. The cross section volume of the energy dissipater shall be equal to or greater than the volume of the drainage at peak flow. This will prevent the water discharge from scouring adjacent stream banks. Unit of payment is based on cubic feet of rock installed. (Refer to energy dissipater installation drawings in specification diagrams.)

Open Rock Culvert Construction

The construction of an open rock or step through culvert begins with the excavation of the culvert opening or trench. The depth of the excavation shall correspond to the dimensions calculated for the maximum flow in a one hundred year event. In addition, the excavation depth must include the thickness of the rock that will be used for the bottom trey of the culvert and the rock used for the sides of the culvert. If additional steps are to be installed, the thickness of those rocks will also have to be accounted for. The bottom and sides of the trench shall be constructed into stable native soil and be free of organics, rotten wood or fill material. Once the trench is excavated to the appropriate dimensions, then the bottom trey of the culvert is laid. This trey is considered rock armoring (as per armored drain swales) and is installed the same manner. Once the trey is installed the sides of the rock culvert are laid. Side wall rocks shall have at least one flat side and be even across one end. The bottom of these rocks shall be a minimum of 6” below the top of the rock trey to help lock the structure together.

The height of these rocks shall be sufficient to provide the 6” depth below the top of the rock trey and the 8” rise of the step. The thickness of these rocks also needs to sufficient to provide a firm and stable platform for the trail user to step off of and on to when crossing over the open culvert. The minimum thickness of the side wall rocks shall be 8”. Rocks selected shall fit together snugly and be placed to provide a firm bearing on adjacent stones. Spalls shall be used as needed to fill voids. All voids behind the sidewalls should be completely filled with crushed rock and firmly compacted. If additional steps are required the height of the side wall rock shall factor in the thickness of the next rock trey that will be constructed on top of it. The total height of these two

structures combined shall be 8” above the bottom rock trey. The next rock trey is constructed starting on the outside edge of the side wall rock. This trey extends into the hillslope a minimum of 13” or up to the maximum width of 18”. A second rock side wall is then constructed on the inside of the rock trey. This side wall shall begin a minimum of 6” below the top of the trey and extend 8” above the top of the second trey. To complete the installation of this step through culvert a similar rock trey and step shall be constructed on the other side of the open rock culvert. The same construction techniques used to finish the bottom trey and side walls shall be applied to the second trey and sidewalls. If an additional rock trey and step is required it shall be installed in the same fashion. Unit of payment is based on cubic feet of rock constructed. (Refer to open rock culvert and step through drain drawings in specification diagrams.)

Armored Swale Construction

Armored drain swales shall be installed by first excavating the crossing and the approaching banks to a minimum depth of 1 foot. The excavation shall match the slope or gradient of the drainage crossing so that the finished rip rap elevation will precisely match the channel of the drainage. The width of the excavation shall extend a minimum of 1 foot beyond the prescribed tread width for the trail. At a minimum the rock shall be installed above any perceivable high water mark. The stones used in an armored drain swale shall be a minimum of 1 foot in depth and 1 foot in width. The initial stones are laid at the lowest point of the structure. These key stones shall be the largest stones within the structure. The stones are placed so that their tops or surfaces match the existing channel elevation. The orientation of the stones shall result in the flattest surface being exposed on top. The next stones are selected and placed to achieve a tight fit against the previous. The gap between these rocks shall be a maximum of ½ inch. The surface of the rocks shall match each other and conform to the channel gradient. Once all the stones are laid in this fashion rock wedges shall be driven along the outside edge of the structure to fill any voids and further tighten the rocks against each other. The stones shall be chinked by pounding pieces of crushed rock into the voids between the rocks until the surface of the structure is relatively uniform and smooth. Unit of payment is based on cubic feet of rock constructed. (Refer to armored drain swale and stream crossing drawings in specification diagrams.)

Armored Stream Crossing Construction

Armored stream crossings shall be installed by first excavating the crossing and the approaching banks to a minimum depth of 1.5 foot. The excavation shall match the slope or gradient of the stream crossing so that the finished rip rap elevation will precisely match the channel of the drainage. The width of the excavation shall extend a minimum of 1 foot beyond the prescribed tread width for the trail. At a minimum the rock shall be installed above any perceivable high water mark. The stones used in an armored stream crossing shall be a minimum of 1.5 foot in depth and 1 foot in width. In more dynamic streams larger stones may be required. The initial stones are laid at the lowest point of the structure.

These key stones shall be the largest stones within the structure. The stones are placed so that their tops or surfaces match the existing channel elevation. The orientation of the stones shall result in the flattest surface being exposed on top. The next stones are selected and placed to achieve a tight fit against the previous. The gap between these rocks shall be a maximum of ½ inch. The surface of the rocks shall match each other and conform to the channel gradient. Once all the stones are laid in this fashion rock wedges shall be driven along the outside edge of the structure to fill any voids and further tighten the rocks against each other. The stones shall be chinked by pounding pieces of crushed rock into the voids between the rocks until the surface of the rip rap structure is relatively uniform and smooth. Unit of payment is based on cubic feet of rock constructed. (Refer to armored drain swale and stream crossing drawings in specification diagrams.)

Step Stone Crossing Construction

The initial step stones shall be placed at the edge of the stream bank. The depth of the excavated footing for these stones shall be a minimum of 1’ below the thalweg of the stream channel. A minimum of one third of the stones mass shall be below the elevation of the streambed. The stones in the channel shall be spaced a maximum of 3’ apart. All excavated gravel and soil shall be exported out of the influence of the drainage. The stones shall be large enough that they project above the anticipated high water levels. The stones selected for these steps shall have greater mass towards their bottoms to provide a lower center of gravity. The stones shall be large enough to be stable during peak stream flows. The tops of the stones shall have the surface area needed for secure footing.

Once placed, the top of the stones shall be approximately level to each other to facilitate easier and safer use by the hikers. Unit of payment is based on cubic feet of rock installed (Refer to step stone installation drawings in specification diagrams.)

Drainage Ditch Construction

The excavation an inboard ditch shall not encroach into the base of the cutbank or in any way undermine or destabilize it. The material excavated when constructing a ditch shall be incorporated into the elevated trail tread or exported away from the saturated area to a location where it can be used as fill in another trail structure or dispersed below the trail. Once the ditch has been excavated to the proper depth and width the banks of the ditch shall be laid back to an angle where the soil is stable and will not sluff. The slope of the ditch shall be nearly equal to the trail grade. When approaching a cross drain structure, the ditches grade shall gradually increase in order to obtain the elevation of the cross drain. If ditch gradients are steep enough to generate water velocities that can scour the ditch and mobilize soils, the bottom and sides of the ditch shall be armored with rock. This rock shall be placed in the same manner as rock armoring but the surface is very rough to reduce water velocities. Stones used in this application should have irregular surfaces that project 1 to 3 inches into the current. Unit of payment is based on lineal feet of ditch installed. Payment for rock armoring is

20 covered separately under armored drain swale construction. (Refer to drainage ditch installation drawings in specification diagrams.)

Waterbar Construction

Water bars shall be constructed to a height of 7” to 8” above trail grade. The upslope and downslope ends shall be designed to fully cross the trail bed to prevent water or the hiker and equestrian from going around the water bar. To determine the angle of a water bar across the trail, begin with 20 degrees and add a degree for each percent of grade of the trail section up to a maximum of 40 degrees. Regardless of the material used, the construction of a water bar requires a trench to provide a stable footing for the structure. Wood, plastic and wood plastic composites are shall be a minimum 4” x 10” dimension. They shall be installed by pre drilling three holes (through the ends and center of the member), placing them in the trench, pinning them with lengths of 5/8” rebar through the holes and then shaping and compacting the soil around them. When using rocks for water bars, they shall have uniform surfaces with at least one surface that has a 90 degree angle. Lay the rocks with as much contact between rocks as possible. The lower portion of the rocks shall be buried in the trench and chinked tight. The rocks shall be placed so that the points of contact overlap with the flow of water. Rocks shall be laid in their most stable position with the main portion of the weight down and in the trench. Fill behind the water bar and chink it tight. Supplemental materials such as a rock tray in front of the water bar may be necessary to provide additional stability to the water bar in unstable areas or on steep gradients.

When finished the downhill side of the water bar will be at trail grade and uphill side will be a minimum of 7” below downhill trail grade. Unit of payment for wood waterbar installation is based on each waterbar installed and the trail width. Unit of payment for rock waterbars installed is based on cubic feet of rock installed. (Refer to waterbar installation drawings in specification diagrams.)

Drain Dip Construction

Drain dip construction begins on the up trail side with a normal outslope. The outslope is gradually increased to (18%) as the trail grade is cut and lowered to the trough and drainpoint. The length and the degree of outslope used in the drain dip shall be determined by the contract’s representative. The trough of the dip is dug across and down the trail at a 30 to 40 degree angle. It shall also be dug with an 18% outslope to insure adequate drainage and sediment transport. From the trough, the down trail side rises at a 5% linear grade to match the original trail grade and outslope. The angle of this reversal leg shall have a minimum length of 30’. Work also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Unit of payment is by each structure, method of construction (mechanized or hand labor) and tread width. Armored drain dip construction is a separate cost item and is covered under armored swale construction. (Refer to drain dip drawing in the specification diagrams).

Rolling Grade Dip Construction

Rolling grade dip construction begins a minimum of 15 feet on the up trail side of the dip with a minimum 20% outslope. The outslope is gradually increased to 30% as the trail grade is cut and lowered to the trough and drainpoint. The length and the degree of outslope used in the rolling grade dip shall be determined by the contract’s representative. The trough of the dip is dug across and down the trail at a 30 to 40 degree angle. It shall also be dug with a 30% downslope to insure adequate drainage and sediment transport. From the trough, the down trail side rises at a 10% linear grade to match the original trail grade and outslope. The angle of this reversal leg shall have a minimum length of 15’. Work also includes shaping and compacting the trail’s tread, cutbank and soil below the outboard hinge. Finished trail tread shall be mineral soil, free of organics, uniformly smooth, compacted and without holes, rock/root protrusions and concave depressions that can trap water. Unit of payment is by each structure, method of construction (mechanized or hand labor) and tread width. (Refer to rolling grade dip drawing in the specification diagrams).

Single Tier Rock Retaining Wall Construction

The construction of a single tier rock wall begins with the excavation of the foundation or footing. The location of the footing should be such that when the structure is completed, the distance from the inboard hinge of the trail to the outside edge of the structure provides the designed trail bed width. The elevation of the bottom of the footing should be set so that the top of the wall is lower than the outboard hinge of the trail. If it is not possible to excavate a level footing, begin construction by placing rocks at the lowest point of the footing.

Install the largest rocks first to serve as keystones to buttress the rest of the rocks. All the rocks should be placed so that their mass is on the inboard side of the footing (into the hill slope). Prior to placing rocks in the footing, the bottom of the footing can be further excavated and shaped so the finished elevation of the rock is level with the rock next to it. The bottoms of the rocks do not need to be flat, since the footing will be shaped to accommodate them, but the tops need to be reasonably flat as these faces serve as part of the trail bed. The sides of the rocks must be shaped so that they make good contact with the rocks next to them. Full contact along both sides of adjoining rocks is preferable, but if only limited contact can be accomplished, it must be toward the tops of the two rocks so the contact (friction) will lock the two rocks together and prevent them from rolling forward. Once the rocks are in the footing, any gaps remaining between the rocks are filled by inserting small wedge-shaped rocks into the gaps (“chinking”). This process provides additional friction between the rocks and further locks them together. The addition of small rocks should be done carefully. Inserting too large of a rock into a gap can wedge the rocks apart.

Chink the back of the wall first and then the front. Once this task is completed, the trench can be backfilled with crushed rock and soil and the material is compacted in maximum 3-inch lifts. Unit of payment is based on cubic feet of rock wall constructed. (Refer to single tier rock retaining wall drawings in specification diagrams.)

Multi Tier Rock Retaining Wall Construction

The location of the foundation is laid out so that the wall begins below the trail and far enough away from the outboard hinge of the trail so that when the wall is finished the top of the wall is below the outboard hinge of the trail. The layout should account for the overall height of the wall and the batter being applied.

The foundation or footing for a multi-tier rock retaining wall shall be excavated into stable mineral soil and be level from side to side or across the horizon. The bottom of the foundation shall be tilted to the rear or back of the wall, a minimum of 5 percent. The foundation is excavated so that it is level. However, protruding bedrock or large boulders can cause the foundation to slant to one side. In this case, start the wall at the lowest end of the footing. The first rock laid should be a substantial size, as it will become the keystone that buttresses the rest of the wall. Because the top of the wall is slanted, it is often necessary to pin the second rock onto the first (bottom) and to continue pinning seceding tiers to keep the rocks anchored to the rocks beneath them and prevent them from sliding downhill. The pinning is achieved by drilling a 7/8-inch hole through the second tier rock and halfway into the first tier rock. Once the hole is cleaned out, a 3/4- inch diameter stainless steel rod is inserted into the hole and glued in place with two part epoxy glue. When installing pins, it is important that the top of the hole is completely sealed with epoxy glue to keep water out of the hole, which can lead to fracturing in below freezing conditions. The first tier of rock needs three good surfaces for making contact: the ends for contact with the rocks next to it, and the top for contact with the next tier. The bottom of the rocks can be of irregular shape, as they are buried at the bottom of the footing. Foundation rocks are laid so that they do not overhang or protrude beyond the front of the footing. Set foundation rocks so they are firm and stable and have good contact with the wall rock next to them. Full contact along the face of adjoining rocks is preferable. If full contact is not possible, there should at least be solid contact between the upper portions (high contacts) of the two rocks. The top of the foundation tier must be flat to provide good contact and a solid base for the next tier of rock. All wall rocks should be laid with their greatest dimension extending into the wall. At least one-quarter of the rocks should be “header rocks” or rocks that extend a minimum of two feet into the backfill behind the wall. Once the initial foundation is complete, the back of the wall is filled with crushed rock. The smaller fractured rock is then stuffed behind the wall rock in a fashion that does not move or disturb the wall rocks or compromise their points of contact, so that all voids are filled with crushed angular rock and the backs of the wall rocks are fully supported. The remainder of the footing behind the wall is filled with crushed rock to the same elevation as the wall rocks. Test the wall rocks for stability by walking along the outer (front) edge of the rocks and checking for movement or rocking. When a worker’s full weight is placed on the outer edge, the rocks should not move or tilt. If movement occurs, the cause must be identified and corrected prior to proceeding to the next tier.

Rocks placed on top of the first tier need to reflect the prescribed batter. Installing the second tier is similar to installing the foundation except that there must be solid contact between the top of the foundation rocks and the bottom of the second tier rocks. To

23 ensure wall stability, each rock placed in the upper tier should have a minimum of three contact points with the lower tier. The rocks in the second tier must span the joints between rocks in the foundation tier. The second tier must also maintain the minimum 5% rearward tilt that transfers the weight off the wall and into the hill slope. Once the second tier is complete, the back of the wall is carefully chinked and voids are filled with appropriately sized crushed rock. When the backs of the wall rocks are stuffed and supported, the remainder of the footing behind the wall is filled with crushed rock to the same elevation as the second tier wall rocks. Subsequent tiers are constructed in a similar fashion until the designed height is achieved. The top of the retaining wall affects the trail bed drainage design. If the trail bed is outsloped, the top of the wall must be lower in elevation than the outboard hinge of the trail tread. Once the wall is complete, the front of the wall can be chinked by placing rock wedges into the gaps left between rocks to add stability. Chinking is performed only after the wall is complete. Chinking is not intended to fill every gap in the face of the retaining wall; only the largest ones. Gaps are necessary to provide drainage from the back of the wall and to relieve pore pressure. Fill material behind the wall should be rock and/or mineral soil, with the final 4 inches consisting of material not larger than 2 inches. All voids should be filled and the material compacted. Unit of payment is based on cubic feet of rock wall constructed. (Refer to multi-tier rock retaining wall drawings in specification diagrams.)

Multi Tier Mortared Rock Retaining Wall Construction

The foundation or footing for a multi tier mortared rock retaining wall shall be excavated into stable mineral soil and be level from side to side or across the horizon. The bottom of the foundation shall be tilted to the rear or back of the wall, a minimum of 5 percent. The initial foundation wall rock course shall be laid on top of a wet layer of concrete a minimum of twelve inches thick.

Reinforcement steel, wire or fiberglass fabric shall be required in this concrete pour. The concrete shall be wet enough that the rocks will partially sink into it but stiff enough to support the rocks. Before rocks are used in the retaining wall they shall be thoroughly wire brushed and washed with water to provide clean surfaces that the concrete and mortar will readily adhere to. If designated by the state’s representative, Muratic acid shall be used to clean the rocks when the surfaces are particularly oily or dirty. Good contact between wall rocks shall be required. The largest rocks shall be used in the bottom course. Rocks shall be laid with the bulk for the rock's weight set back into the wall. Foundation rocks shall be laid so that they do not overhang or protrude beyond the front of the footing. The area behind the wall rocks shall be filled with crushed rock or a similar porous aggregate. Before the next course of rock can be laid some form of drainage to remove water from behind the rock wall shall be installed. This shall be accomplished by installing a curtain drain that drains the water from behind the wall to the outside edges of the wall or by installing sections of PVC pipe that extend from the porous backfill to the face of the wall rock. The rocks placed on top of the foundation course shall reflect the batter prescribed by the state’s representative. A string line shall be installed to provide a guide for the starting point or front of the wall rocks in the second course. As the second course is laid solid contact shall be achieved between the top of the foundation rocks and the bottom of the second course of wall rocks. The

joints between the rocks in the foundation course shall be spanned by the rocks in the second course. The second course shall also maintain the minimum 5% rearward tilt. Rocks selected for the second tier shall be wiped with a damp cloth or sponge. A layer of mortar shall then be troweled onto the top of the foundation rocks to provide a bed for the next course of wall rock to lie on. This shall be a thin layer of mortar where there is good contact between the two rocks and a thicker layer where there are voids and poor contact. A layer of mortar shall then be applied to the bottom of the rock being set on the foundation course. Once the top rock is set on top of the foundation course it shall gently taped with the butt of the trowel until it is firmly sitting on the bottom rocks and rock to rock contact is achieved.

Mortar shall then be troweled onto the side of the rock just placed where the next rock will butt against it. This shall be a thin layer where there is good contact and a thicker layer where there are voids. The next wall rock shall then be set in a similar fashion as the first except mortar is troweled onto the side that will be butting up to the rock previously laid. The second rock shall then be pressed against the preceding rock and gently taped with the butt of the trowel until rock to rock contact is made on the bottom and the side adjoining the previous laid rock. This process shall be continued until the second course is completed. As the courses of a mortar retaining wall are constructed they shall adhere to the set back and batter requirements previously identified. Regardless of the mortar style being applied, once the rock has been set and tooled out to the desired finish a wet sponge shall be used to wipe off any excess mortar and clean the exposed rock faces. Unit of payment is based on cubic feet of rock wall constructed. (Refer to multi tier mortared rock retaining wall drawings in specification diagrams.)

Non Structural Rock Retaining Wall

The foundation or footing for a non structural rock retaining wall shall be excavated into stable mineral soil and be level from side to side or across the horizon. The bottom of the foundation shall also be tilted to the rear or back of the wall, a minimum of 5 percent. If the footing cannot be level then the first rock laid shall be of substantial size as it will become the keystone that will buttress the rest of the wall. This rock shall be laid in the lowest end of the wall. The largest rocks shall be used in the bottom course. Rocks shall be laid with the bulk for the rock's weight set back into the wall. Foundation rocks shall be laid so that they do not overhang or protrude beyond the front of the footing. Foundation rocks shall be set so they are firm and stable and have a minimum of two points of contact with the wall rocks next to them. Once the initial foundation course is completed, then the back of the wall shall be stuffed and filled with rock (2”-6” dia.) to a level that maintains the minimum 5% tilt. The next course of rock shall be laid to achieve a minimum batter of 45 degrees or a one to one slope. Rocks in the second course shall be laid to have a minimum of three points of contact with the rocks below and to the side of them. Additional courses shall be laid in the same manner until the desired wall height is achieved. The top course shall be laid so the rocks will not move or tilt when stepped upon. Unit of payment is based on cubic feet of rock wall constructed. (Refer to non structural rock retaining wall drawings in specification diagrams.)

Wood/Plastic Wood, and Log Interlocking Retaining Wall (Structural)

The foundation must be laid out so that the wall, which begins below the trail, will start far enough out from the outboard hinge. When it is finished, the top of the wall must terminate at or just below the outboard hinge of the trail. This layout must account for the overall height of the wall and the batter (if used). The foundation shall be excavated into stable mineral soil and be level. Each course of a multi tier retaining wall may consist of facers, wings and anchor post. Each wall course shall be interlocked through the use of notching and be notched so that there is a one inch gap between each facer and wing course. The anchor post shall be notched so that it is installed at a 10% downward angle. The notching shall be performed so that the faces of all interlocking members fit tightly together and have uniform contact where the notches join together each structural member. Due to the non-uniform shape of logs and split products, layout and notching requires a custom fit for each structural member. On any course, the anchor post shall not be spaced more than 8 feet apart horizontally. The length of the anchor post shall be a minimum of 48”. Where the length of the facer or wing wall is such that two or more facers or wings are spliced together, the splice shall be a lap joint. Splices in the facer and wings in the next course of the wall shall be staggered so that these joints do not occur consecutively.

Anchor posts shall be placed on each side of the splice to provide additional support for these joints. Anchor post shall also be installed so they are staggered and not placed directly above the preceding course. All ends of the retaining walls shall be keyed into native soil a minimum 1’. When joining the facer and wing walls together, the ends of the facer and wing wall members shall extend beyond the notch a minimum of 6 inches. Anchor post ends shall also extend a minimum of 6 inches beyond the notch. As directed by the state’s representative, all wing, facer and anchor post shall be either all heart redwood, cedar, pressure treated Douglas Fir, wood/plastic composite or recycled plastic wood (structural grade) and shall be a minimum of 4 inches thick and a minimum of 8 inches wide or high (if using logs, the minimum all heart diameter shall be 8 inches at the small end. Upon the completion of each multi tier course, the area behind the wall shall be backfilled. Backfill material shall be of sufficient size that it will not sift out between the gaps in the wall. Backfill will consist of permeable aggregate soils or drain rock. Rocks larger than 4 inches shall not be used as backfill material. Unit of payment is based on square feet of retaining wall constructed. This is calculated by measuring the surface area of the facer and wing walls. (Refer to multi tier wood retaining wall drawings in specification diagrams.)

Log Crib Retaining Wall Construction

A footing or trench shall be excavated to contain the log. The elevation of the bottom of the trench shall be set so that the top of the wall when completed will be lower than the outboard hinge of the trail. The depth of the trench shall be a minimum of one third of the height of the log being placed into it. The bottom of the trench shall be shaped to accommodate any of the irregular shapes associated with the log. Logs are placed into the trench and secured by pinning them with rebar. The holes for the rebar (a minimum of two per log) are drilled prior to setting the logs in the trench. The diameter of the hole

26 shall be 1/16 of an inch less than the 5/8” rebar used in pinning the log. The rebar shall be long enough to penetrate a minimum of 2’ into the ground beyond the bottom of the log. Once the log is pinned the back of the wall shall be backfilled with a combination of crushed rock and soil and compacted in maximum 3 inch lifts. Unit of payment is based on the distance the log is moved and square foot of retaining wall/log placed. (Refer to log crib retaining wall drawings in specification diagrams.)

Geotextile Fabric Retaining Wall Construction

Once the contracts representative has completed the layout of the retaining wall and has identified height, width and length of the retaining wall as well as the prescribed number of tiers, tier height and batter the foundation for the wall can be constructed. The excavated width of the foundation for the retaining wall shall be equal to the height of the wall plus provide a bench in front of the retaining wall wide enough to support the soil that will cover the entire face of the structure. Prior to digging activities any vegetation that is suitable for transplanting shall be salvaged from the work area and kept in wet burlap sacks until it can be planted later in the soil placed on top of the face of the retaining wall. All organics and top soil from the excavation area shall be saved for later placement on the completed retaining wall. All B horizon soils shall be saved as backfill material in the retaining wall. When excavating these foundations the minimum rearward tilt into the hillslope shall be 10%. Constructing the geotextile retaining wall shall begin by unrolling a length of fabric that is needed for each tier and cutting that length from the roll. This length of the fabric shall be a minimum of twice the width of the retaining wall tier plus and additional I foot for the face of the wall. The length of the fabric shall be the length of the foundation plus and a minimum of 3 feet of fabric on each end of the wall to fold and seal off the backfill at the ends of the wall. Place one end of these pre-cut lengths of fabric at the inboard hinge of the foundation (the back of the foundation) next to the cut bank, and staple it in place by driving in U shaped pieces of rebar every 4 feet along the inboard hinge of the fabric with a single jack to keep the fabric from moving or being pulled forward. Use a utility knife to cut small holes in the fabric to accommodate the staples. The staples are fabricated from 3/8-inch rebar and are approximately 12 inches wide and 18 inches long. When the fabric is unrolled to where the front of the retaining wall will be, it is left there and is filled with a 1-foot deep layer of the B horizon soil from the initial excavation or imported aggregate. Use tampers or plate compactors to compact this fill material in 2 to 3 inch lifts as it is placed. The earthen banks at the rear and sides of the foundation will help contain the backfill as it is being compacted. Care must be taken at the front of the wall since that area is open until the fabric is folded back on itself. Once the layer of backfill is nearly complete, the fabric at the front of the wall is partially pulled back and temporarily pinned to keep the backfill from spilling out. Continue placing and compacting backfill until the designed thickness of the tier is achieved. Carefully unpin the fabric at the front of the wall, and then fold the sides of the fabric (the extra 3 feet) back on top of the fill material. Using a hospital fold or similar, fold the front of the fabric over the sides and pull the remaining fabric tightly back over the compacted fill to the inboard hinge. Pull the fabric over the fill while maintaining a well-shaped and even-height tier and a uniform front to the face of the wall. U-shaped rebar staples are used to fasten the fabric along the inboard hinge every 4 feet. The next length of fabric is rolled out toward

the front of the wall just as before, but stops short of the previous tier to achieve the prescribed batter determined by the layout calculations. Once again, this length of fabric is filled with backfill to a depth of 1 foot. The backfill is compacted and the sides and front are folded, tucked, pulled back, and stapled. If there is insufficient backfill from the foundation excavation to fill all the layers of the wall, more can be imported from construction or maintenance activities along the trail. The process is repeated with succeeding tiers, each “stepped back” the prescribed batter from previous tiers until the final tier is installed and stapled with U-shaped rebar at the back of the wall.

The top of the finished wall shall be covered with a minimum of one foot of soil suitable for trail tread. The surface shall be shaped and compacted to provide the desired drainage. The front of the wall shall then be covered with top soil. A minimum depth of one foot of soil shall be placed over the front of the wall. The organics shall then be spread over the top soil and if designated by the state’s representative, a layer of jute netting shall be laid over the face of the wall to help contain the top soil. The vegetation salvage earlier shall then be transplanted into the soil. Unit of payment is based on square feet of retaining wall constructed.

This is calculated by measuring the surface area of the wall face. (Refer to geotextile fabric retaining wall drawings in specification diagrams.)

Cellular Confinement Retaining Wall Construction

28 of soil suitable for trail tread. The surface shall be shaped and compacted to provide the desired drainage. The front of the wall shall then be covered with top soil to a minimum depth of one foot. The organics shall then be spread over the top soil and if designated by the state’s representative, a layer of jute netting shall be laid over the face of the wall to help contain the top soil. The vegetation salvage earlier shall then be transplanted into the soil. Unit of payment is based on cubic feet of retaining wall constructed. (Refer to cellular confinement retaining wall drawings in specification diagrams.)

Soldier Pile with Lagging Retaining wall Construction

Once the contracts representative has completed the layout of the retaining wall and has identified height, width and length of the retaining wall, one inch diameter rebar 3’ to 4’ long shall be driven into consolidated ground. The H beam post shall then be set over the rebar with the rebar sliding into the channel in the center of the post. The H beam post shall be driven a minimum of 2’ into the ground or until the finished elevation is achieved for the top of the post. If the retaining structure will be anchored into rock, then a hydraulic, gas, or electric powered drill is used to drill a hole 1 1/8 inches in diameter and 12 inches deep. This hole is cleaned of rock dust, and two-part epoxy glue is squeezed into the hole. A piece of rebar 1-inch in diameter and 2 to 3 feet in length is driven into the hole until it is fully seated. The H beam post is then placed over the rebar.

When the first post is set, wall boards of 2- x 6-inch or 2- x 8-inch and 4 to 5 feet long are placed into the slot on the side of the H beam post. These boards will show the placement of the next H beam post, as they must fit into the channel or slot on its side. Once the location of the next H beam post is identified, the process is repeated. After two posts are installed, the wall boards can be dropped into the slots on the sides of the posts. If the ground between the posts has not been leveled prior to installation, it may be necessary to do so before the first (bottom) board is installed. The starting elevation where the first board will sit must be consistent with the layout, as it will affect the final elevation of the wall.

It is also important to provide a gap between the boards for drainage. The height of the gap in the wall may vary, depending on the anticipated drainage from behind the wall. A 1/2-inch gap between the boards is considered the minimum with a 1-inch gap being preferred. This gap can be established by inserting a piece of metal stock between the wall boards where they set on top of each other inside the post channel. The H beam post shall be anchored into the hillslope with either an earth anchor (in native soils) or an expansion anchor (if in rock).

On soft soil, a hydraulic or gas powered hammer with a gad drive attachment is used to drive an earth anchor (duck billed anchor) into the hill slope behind the wall once the wall boards are installed. The duck billed anchors should have a minimum 3,000-pound capacity. The anchors are driven into the hill slope a minimum of 4 to 6 feet. Use anchors that are designed to attach to 1/2-inch diameter all thread. The all thread is attached to a high lift jack and the jack is used to pull on the all thread and set the duck

29 billed anchor. Setting the duck billed anchor requires pulling it several inches to open the bill. The all thread is run through a hole in the H beam post and attached with nuts and washers. The holes can be pre-drilled, or drilled on-site if the appropriate power tools are available, and placed within 12 inches of the top of the post to provide good leverage once the wall is loaded. The all thread is tightened until the wall is pulled two to three degrees past vertical into the hill slope. Once backfilled, the weight of the backfill will push the wall out to where it is nearly plumb.

When setting anchors in rock, use a hydraulic or gas powered rock drill to drill a 5/8-inch diameter hole a minimum of 3 inches deep into competent rock. Insert an expansion anchor into the hole and set it with a setting tool. Use an anchor that can be attached to a half inch all thread, and attach the all thread to the posts as described above. When the anchors are set, 2-inch channel iron is installed on top of the final wall board and H beam posts to provide a metal cap. The channel iron is pre-cut to length matching the center spacing between the posts, and placed on the wall so that it spans from the center of one H beam post to the center of the next. An electric, gas, or battery powered drill is used to drill a 3/16-inch hole through the channel iron into the post. A 1/4- x 1-inch metal screw fastens the channel iron to the post. This screw can be installed with an electric, gas, or battery powered drill. Once the metal cap is installed, the retaining wall can be backfilled with porous material that allows water to pass through to the front of the wall, where it can seep out through the gaps left in the wall boards. A minimum of 4 inches of fill consisting of the desired tread material is installed on top so that the designed surface drainage is achieved. Unit of payment is based on square feet of retaining wall constructed. This is calculated by measuring the surface area of the wall face. (Refer to soldier pile with lagging retaining wall drawings in specification diagrams.)

Edge Protection (Wood)

This work involves installing log barriers on the outboard hinge of the trail in a fashion that simulates down woody debris in the natural setting. Logs shall be a minimum of six inches in diameter and provide a minimum of 6 inches high barrier. Logs shall be anchored to the ground by using 5/8 inch rebar a minimum length of 3 feet. Logs shall be placed to allow for natural sheet flow and not obstruct trail drainage. Unit of payment is based on lineal feet of log barriers installed.

Edge Protection (Rock)

A footing shall be excavated to contain the rocks. The depth of the footing shall be a minimum of one half of the height of the rocks being placed into it. Rocks shall be a minimum of 18 inches in diameter and provide a barrier a minimum of 6 inches high. The bottom of the footing shall be shaped to accommodate any of the irregular shapes associated with the rocks and be tilted back into the hillslope a minimum of 5%. All the rocks shall be placed so that their mass is on the inboard side of the trench (into the hillslope). Voids around the rock shall be backfilled with a combination of crushed rock and soil and compacted in maximum 3 inch lifts. Rocks shall be placed approximately 4” apart to provide allow sheet flow and not obstruct trail drainage. Unit of payment is

30 based on the cubic feet of rock constructed. (Refer to rock edge protection drawings in specification diagrams.)

Edge Protection (curb)

This work involves installing wood, plastic wood composite or plastic wood barriers on the outboard hinge of a trail. The curbing shall have a minimum dimension of 4” x 4”. The curbing shall project a minimum of six inches above the outside edge of the trail tread. The curbing shall be elevated a minimum of 2 inches above the ground by installing wooden or plastic wood blocks under the curbing. The blocks and curbing shall be anchored to the ground by using 5/8 inch rebar a minimum length of 2 feet. Curbing shall be placed to allow for natural sheet flow and not obstruct trail drainage. Unit of payment is based on lineal feet of curbing installed. (Refer to curbing edge protection drawings in specification diagrams.)

Pinch Point (Rock)

A footing shall be excavated to contain the rocks. The depth of the footing shall be a minimum of one third of the height of the rocks being placed into it. Rocks shall be a minimum of 30 inches in diameter and project a minimum of 20 inches above trail grade. The bottom of the footing shall be shaped to accommodate any of the irregular shapes associated with the rocks and be tilted back into the hillslope a minimum of 5%. All the rocks shall be placed so that their mass is on the inboard side of the trench (into the hillslope). Voids around the rock shall be backfilled with a combination of crushed rock and soil and compacted in maximum 6 inch lifts. These rocks are to be placed above and below the trail bed where the trail curves or turns. The rocks are offset, with one being further up or down the trail from the other, and placed outside of the designed width of the trail tread. When placed in this way, these objects will appear to the rider as adjacent with only a narrow opening between them. Unit of payment is based on the cubic feet of rock constructed and distance moved. (Refer to pinch point construction drawings in specification diagrams.)

Pinch Point (log)

A footing or trench shall be excavated to contain the log. The depth of the trench shall be a minimum of one third of the height of the log being placed into it. The bottom of the trench shall be shaped to accommodate any of the irregular shapes associated with the log. Logs shall be a minimum of 30 inches in diameter and project a minimum of 20 inches above trail grade. Logs are placed into the trench and secured by pinning them with rebar. The holes for the rebar (a minimum of two per log) are drilled prior to setting the logs in the trench. The diameter of the hole shall be 1/16 of an inch less than the 5/8” rebar used in pinning the log. The rebar shall be long enough to penetrate a minimum of 2’ into the ground beyond the bottom of the log. These logs are to be placed above and below the trail bed where the trail curves or turns. The logs are offset, with one being further up or down the trail from the other, and placed outside of the designed width of the trail tread. When placed in this way, these objects will appear to the rider as adjacent with only a narrow opening between them. Unit of payment is

based on the distance the log is moved and square foot of log placed. (Refer to pinch point construction drawings in specification diagrams.)

Wood Step Construction

The installation of wood steps shall follow the layout for step rises and tread depths designed by the contract’s representative To install wooden steps, start at the bottom of the carriage where the initial layout identified the beginning of the steps. The initial step is placed into a shallow footing approximately 1 inch in depth that is excavated and sized for the specific step. If the steps are being installed with an inslope or outslope, the footing excavation needs to extend into the cut bank 6 inches. If the steps are being installed straight up the hillslope (through cut), the footing excavation needs to extend into the hillslope 6 inches on both sides of the step. The footing should be level from front to back, have the same cross slope as the desired finished step, and be perpendicular to the trail alignment. Do not over-excavate, as it creates the need for fill material to achieve the desired elevation. Any loose soil will result in an unstable foundation. The soil in the bottom of the footing should be compacted for stability. Wooden steps should span the entire trail width, ensuring that backfilled soil is contained and that there is no room for trail users to circumvent the step. Prior to placing the step into the footing, drill 9/16-inch pilot holes on center through the step, approximately 6 inches from each end of the step. The step is placed in the footing and checked with a carpenter’s level to ensure that it is level from front to back and has the desired cross slope. Once the step is placed in the footing, it is pinned with 5/8- x 36- inch rebar. With the step secured, the uphill side is backfilled with soil from the next step excavation. If more durable backfill material such as crushed rock is required, install it behind the step and export the soil from the step excavation above to a suitable location. When steps are placed in a series, the bottom of the upper step is one inch lower than the top of the lower step. This overlap reduces undermining of the upper step by mechanical wear, helps lock in backfill material, and prevents water from collecting behind the steps. For proper drainage, the final elevation and grade of the backfill material or tread should have the same cross slope as the steps. If a drain or ditch is constructed to channel runoff from the steps, large angular rocks are best for filling any ditch, as they provide the most voids to allow water to pass and discourage trail users from walking outside the steps. Unit of payment is based on each individual step installed. (Refer to wood step construction drawings in the specification diagrams.)

Interlocking Wood Step Single Crib Construction

The installation of interlocking wood steps with one crib shall follow the layout for step rises and tread depths designed by the contract’s representative. The first step shall be installed at the bottom of the slope or step carriage. The initial step shall be placed into a shallow trench (approximately 1” in depth) that is excavated and sized for the wood step. The trench shall be level front to back and have the same cross slope as the desired finished step. The step trench shall be free of organics and be uniformly smooth and well compacted. A second trench perpendicular to the step and located on the outside edge of the trail tread shall be excavated. Prior to placing the step into the trench, the outside end of the step and the interlocking crib member shall be joined

32 together with a lap joint so that half the thickness of each wooden member is removed or notched out. A 9/16” pilot hole shall be drilled through the step and the crib member where they joint together. Another 9/16”” pilot hole shall be drilled through the step on center and approximately 3” from the inside edge of the step. The step shall be set into the ground perpendicular to the trail alignment and the crib member shall be under it to form the lap joint. Wood steps shall be installed so that the entire width of the trail bed is spanned and the inside end of the step is inset into the cutbank a minimum of 6 inches. When the step and the crib member are placed into their trenches they shall be checked with a level to insure that they are level front to back and have the desired cross slope. They shall be pinned at the lap joint and the inside edge of the step with 5/8” rebar long enough to penetrate a minimum of 28” into the ground beyond the bottom of the step. The uphill side shall be backfilled with the soil from the next step and crib member excavation. The final elevation and grade of the backfill material (tread) shall have the same cross slope as the steps to insure proper drainage. If more durable backfill material is specified by the state’s representative such as crushed rock then that material shall be installed behind the step and the soil from the step excavation above is exported. When steps are placed in a series, the bottom outside edge of the next step shall set flush on top of the crib member previously placed. This second step and corresponding crib member are installed in the same manner as the first but a pilot hole shall be drilled through the lap joint and the crib member under the lap joint. The step and the crib members shall be pinned with rebar in the same manner as the first step. The remaining steps in the carriage are laid in the same manner until final or top step is laid. All steps in the same run shall have the same vertical rise and tread depth. Unit of payment is based on each individual step installed. (Refer to interlocking wood step construction drawings in the specification diagrams.)

Interlocking Wood Step Double Crib Construction

The installation of interlocking wood steps with two cribs shall follow the layout for step rises and tread depths designed by the contract’s representative. The first step shall be installed at the bottom of the slope or step carriage. The initial step shall be placed into a shallow trench (approximately 1” in depth) that is excavated and sized for the wood step. The trench shall be level front to back and have they same cross slope as the desired finished step. The step trench shall be free of organics and be uniformly smooth and well compacted. Two additional trenches perpendicular to the step and located on the outside and inside edge of the trail tread shall be excavated. Prior to placing the step into the trench, the outside ends of the step and the interlocking crib members shall be joined together with a lap joint so that half the thickness of each wooden member is removed or notched out. A 9/16” pilot hole shall be drilled through the step and the crib member where they joint together. The step shall be set into the ground perpendicular to the trail alignment and the crib members shall be set under it to form the lap joints. Wood steps shall be installed so that the entire width of the trail bed is spanned. When the step and the crib members are placed into their trenches they shall be checked with a level to insure that they are level front to back and have the desired cross slope. They shall be pinned at the lap joints with rebar long enough to penetrate a minimum of 28” into the ground beyond the bottom of the step. The uphill side shall be backfilled with the soil from the next step and crib member excavation. The final elevation and grade of

33 the backfill material (tread) shall have the same cross slope as the steps. If more durable backfill material is specified by the state’s representative such as crushed rock then that material shall be installed behind the step and the soil from the step excavation above is exported. When steps are placed in a series, the bottom of the next step shall set flush on top of the crib members previously placed. This second step and corresponding crib members shall be installed in the same manner as the first but a pilot hole is now drilled through the lap joints and the crib members under the lap joint. The step and the crib members shall be pinned with rebar in the same manner as the first step. The remaining steps in the carriage shall be laid in the same manner until the final or top step is laid. All steps in the same run shall have the same vertical rise and tread depth. Unit of payment is based on each individual step installed. (Refer to interlocking wood step construction drawings in the specification diagrams.)

Interlocking Wood Step Full Crib Construction

Following the rise and run layout of the state’s representative, crib wall, step and anchor members shall be installed to provide a uniform step rise and tread depth throughout the entire carriage. Fully cribbed steps are constructed with milled redwood or cedar; pressure treated lumber, or structural plastic lumber. The full crib steps shall be constructed by excavating footings for the two outside crib walls. The footings shall be excavated into mineral soil and be free of organics. They shall be wide enough to fully support a 4” x 8” crib wall member and the bottom of the footings shall be uniformly flat and level front to back and side to side. The depth of the crib wall footings shall be adequate to recess the crib members 3” to 4” into the ground. The step material needs to be 4- x 8-inch stock. The length of the cribbed wall stock is dictated by the height of the carriage and the site where it will be constructed. The length of the steps and anchor post members need to be no less than 18 inches longer than the desired step tread width. The additional length is required for the 4-inch width of the notch on the cribbed wall (full dimension lumber) and the 5-inch overhang on the outside of the cribbed walls. The two outside cribbed walls are unitized (connected) by steps and anchor posts. The step member spans between the two cribbed walls and serves the function of the step riser as well as a facer. The anchor post also spans between the two cribbed walls (further into the structure, behind the steps). It ties the two cribbed walls together and provides additional rigidity and structural integrity to the carriage. The steps and anchor posts are notched into the cribbed walls.

Both the step/anchor post and the cribbed wall are notched to a depth of 3 3/4 inches (with full dimension lumber) so that when the two members are seated together a 1/2- inch gap remains between the cribbed wall members. The steps and anchor post shall be notched into the crib walls so that the ends of the anchor post and step member extend a minimum of 5” beyond the outside of the crib wall. The notching shall be performed so that the faces of all interlocking members fit tightly together and have uniform contact where the notches join together each structural member. Fill material placed inside the cribbed walls consists of 2- to 3-inch washed drain rock. The washed drain rock is capped with 3” of clean 1 ½” aggregate to provide a uniform tread surface. The gap between the cribbed wall members is to allow surface drainage to flow freely through the drain rock and out of the structure. This notching pattern also results in the

34 step being evenly spaced between two outside cribbed walls. This spacing is required so the cribbed wall frames in the step tread and retains the step backfill material. Unit of payment is based on each individual step installed. (Refer to full crib interlocking wood step construction drawings in the specification diagrams.)

Cable Step Construction

The installation of cable steps shall follow the layout for step rises and tread depths designed by the contract’s representative. The maximum rise per step shall be 8 inches and the treads shall be 13 inches to 18 inches. All steps in the same run shall have the same vertical rise and tread depth. Once the layout has been determined, “dead man anchors” are installed a minimum of 18 inches into the ground at each end of the step carriage. These anchors are 6- x 6-inch timbers cut to the same length as the steps. Drill holes through the center of the dead man timbers 3 inches from each end. Two galvanized wire ropes 3/8 inch in diameter are then passed through each hole on the upper anchor, wrapped half way around the timber and then secured with 3/8-inch wire rope clips. The two galvanized wires are then draped down the hillslope. The cable step material is made from 6- x 6-inch construction heart redwood or cedar, with the edges cut at a 45 degree angle for an even-sided octagon. Drill 1/2-inch diameter holes through the center of each step 3 inches from each end. Where the step carriage will be constructed, the required number of steps should be laid out on the hillslope. Pass the ends of the galvanized wire rope through the holes in the steps. Leave enough space on the ground and slack in the wire rope to make adjustments. Note, when the wire rope is cut to length for this carriage, braze or wrap duct tape around the cut ends to prevent unraveling and make it easier to pass through the holes in the steps. Using the previously determined tread depth, slide the top step up the wire rope to the appropriate distance from the top anchor. Adjust the underlying ground to achieve a roughly shaped tread and rise. The maximum rise per step shall be 8 inches and the treads shall be 13 inches to 18 inches. Once the steps has the required rise and tread depth, secure it in place by attaching a wire rope clip to the wire rope where it exits the underside of the step. The clip will keep the step from sliding further down the wire rope. Install the remaining steps following this process working from the top step down. Maintaining some downward tension on the wire ropes as steps are set will also maintain stability and minimize settling when backfilling. Some locations require importing material suitable for placement beneath the step carriage, so that a reasonable rise and run are obtained. If the parent material is sand, sand bags will help support the structure. Once all the steps have been installed, the remaining wire rope is passed through the holes in the bottom anchor and secured in the same manner as the top anchor. Unit of payment is based on each individual step installed. (Refer to cable step construction drawings in the specification diagrams.)

Cut-out Stringer Step Construction

The installation of cut-out stringer steps shall follow the layout for step rises and tread depths designed by the contract’s representative. The layout for cutting out the step stringers shall be performed with a steel framing square. The body or large end of the square shall be placed on the side of the stringer and moved up or down until the outer

12 inch mark is at the top edge of the stringer. The tongue or small end of the square shall then be moved until the outer 8 inch mark is at the top edge of the stringer. Once the square has been placed in this manner, lines shall be scribed along the outer edge of the tongue and body until they meet at the heel of the square. The tongue line represents the rise and the body line represents the tread. On the first step, the body line shall be carried to the bottom edge of the stringer. This line represents the bottom end of the stringer. Once cut, it shall rest on the mud sill. The next step shall be laid out in the same manner with the 12 inch mark of the body being placed at the top edge of the first rise. Once the lines are scribed, this layout procedure shall be repeated until all the steps in the stairway are scribed. When the last rise is reached, the line shall be extended to the bottom edge of the stringer. Once cut, it shall rest against the end of the bridge stringer. When the layout is complete, the height of the bottom step must be shortened by the thickness of the step material. The cut is made along the bottom of the step stringer where it attaches to the mudsill. Next, the rest of the steps are cut from the step stringer. The minimum depth of wood left below the tread and riser notch is 4 inches. After both step stringers are cut out, they are fastened to the mudsill and the bridge stringers by “toe nailing” with 40d galvanized nails or by using Simpson beam hangers with 40d nails. The width of the steps is the same as the bridge tread.

Tread on the stairway carriage is constructed level in all directions to reduce the chance of slipping when the surface is wet. Water drains off all four edges of the tread. All steps in the same run shall have the same vertical rise and tread depth. Unit of payment is based on each individual step installed. (Refer to cut- out stringer step construction drawings in the specification diagrams.)

Rock Steps Structural Framed Construction

The installation of structural framed rock steps shall follow the layout for step rises and treads designed by the contract’s representative. The installation of rock framed steps shall begin at the bottom of the carriage. Individual rock steps set into the ground shall have at least one flat surface to serve as the tread and one 90 degree face from that flat surface to serve as the front of the step. The first step shall be the key stone that buttresses the entire carriage. This step shall be well anchored and have the mass to support the steps above. Prior to placing the rock, a footing shall be excavated so that the majority of the weight of this rock will be below grade. This excavation shall match the shape of the bottom of the rock so it sits snugly into the earth. No loose soils shall exist within the excavation and all voids shall be filled with crushed rock to prevent settling. Once the step rock is installed, wall rocks shall be installed on both sides of the step to lock it into the hillslope. These rocks shall be placed in a footing that has been excavated to facilitate the dimensions of the rock’s bottom and width. These framing rocks shall be initially installed at the bottom of the carriage and their installation coincides with the step rocks. The bottom framing rocks shall be placed on both sides of the step rock and serve as key stones for the framing rock installed above. The framing rocks shall be laid on end and are wedged tight into the footing using chinking rocks. All joints are broken and good contact along the interface between the upper and lower framing rock and the step rock shall be obtained. All steps in the same run shall have the same vertical rise and tread depth. Unit of payment is based on cubic feet of rock

installed. (Refer to structural framed rock step construction drawings in the specification diagrams.)

Equestrian Rock Steps Structural Framed Construction

The installation of equestrian structural framed rock steps shall follow the layout for step rises and treads designed by the contract’s representative. The construction of equestrian rock framed steps are the same as standard rock framed steps, except the step treads must be 48 inches deep and transition landings must be 96 inches deep. The step width on equestrian trails should be a minimum of 48 inches with 60 inches being the optimal width. Additional requirements for construction of equestrian steps include the use of erosion- resistant backfill material. All steps in the same run shall have the same vertical rise and tread depth. Unit of payment is based on cubic feet of rock installed. (Refer to equestrian structural framed rock step construction drawings in the specification diagrams.)

Rock and Riser Step Construction

The installation of rock and riser steps shall follow the layout for step rises and treads designed by the contract’s representative. The first step is the keystone that buttresses the entire carriage. This step is well-anchored and has the mass to support the steps above it. Before placing the rock, a footing is excavated so that approximately one-third of the mass of the rock is below grade and tilted into the hillslope by approximately 5%. The rock lies back into the hillslope and produces an inward and downward force, rather than outward and downward.

The excavation must match the bottom of the rock so it sits snugly in the ground. Be careful not to over excavate the footing because backfill will then be required to bring the footing to the proper grade. If backfill is required to adjust the elevation of the footing or fill voids, use well compacted aggregate to prevent settling. Once placed into the footing, the rock must have the required rise above the approaching trail tread. The top of the step must be level from front to back or tilted slightly backwards by approximately 5%. If a cross slope is required for drainage, the rock is set to have the appropriate cross slope. Additional steps are installed in the same manner. The excavation for the next step is such that once the second step is placed, the top of the rock is the required rise above the first rock step and the front of the rock is the required distance from the front of the first step rock (i.e., provides the required tread depth). If more than one rock is required to construct a step, there must be good contact between the adjoining rock faces. At a minimum, the two rocks must have good contact at the top and rear of adjoining rock faces so the rocks will not roll forward when weight or force is applied to the top front edge of the step. Additionally, the face of the rocks should not overhang the lower steps. The overhang provides leverage for displacing the rock if the front of the overhanging rock is stepped on. Continue the carriage construction in the same manner, making certain that the rise and run are the same for each step, all joints are broken and that the bottom of the top step is set below the top of the lower step. Unit of payment is based on cubic feet of rock installed. (Refer to rock and riser step construction drawings in the specification diagrams.)

Overlapping Rock Step Construction

The installation of overlapping rock steps shall follow the layout for step rises and treads designed by the contract’s representative. The installation shall begin at the bottom of the carriage. The first step shall be the key stone that buttresses the entire carriage. This step shall be well anchored and have the mass to support the steps above. Prior to placing the rock, a footing shall be excavated so that the majority of the weight of this rock will be below grade and tilted into the hillslope a minimum of 5%. This excavation shall match the shape of the bottom of the rock so it sits snugly into the earth. No loose soils shall exist within the excavation and all voids shall be filled with crushed rock to prevent settling.

Overlapping rock steps shall be installed so that these steps are interlocked by having the front of the top step laid over the back of the bottom step. Rocks used in an overlapping rock step design shall have two flat sides (one to facilitate good contact with the rock below and one to serve as the tread and provide good contact with the rock above). Rocks used in this design shall have a thickness that is consistent with the desired rise of each step. The overlap of the two steps shall be a minimum of 25% of the tread length. Contact between the two rock surfaces shall be sufficient to provide even support for the upper step and all joints are broken. All steps in the same run shall have the same vertical rise and tread width. Unit of payment is based on cubic feet of rock installed. (Refer to overlapping rock step construction drawings in the specification diagrams.)

Rock Step Landing (Hardening) Construction

The footing for the rock step landing is excavated per the dimensions of the landing in the trail work log. The width of the landing shall be equal to the designed width of the trail steps. The stones used in the step landing shall be a minimum of 8 inches in depth and 1 foot in width. The initial stones are laid at the lowest point of the structure. These key stones shall be the largest stones within the structure. The stones are placed so that their tops or surfaces match the existing trail tread elevation. The orientation of the stones shall result in the flattest surface being exposed on top. The next stones are selected and placed to achieve a tight fit against the previous. The gap between these rocks shall be a maximum of ½ inch. The surface of the rocks shall match each other and conform to the trail tread gradient. Once all the stones are laid in this fashion rock wedges shall be driven along the outside edge of the structure to fill any voids and further tighten the rocks against each other. The stones shall be chinked by pounding pieces of crushed rock into the voids between the rocks until the surface of the structure is relatively uniform and smooth. Unit of payment is based on cubic feet of rock constructed. (Refer to the Harden Trail Approach drawing in specification diagram.)

Aggregate Step Landing (Hardening) Construction

The footing for the aggregate step landing is excavated per the dimensions of the landing in the trail work log. The depth of the footing shall be sufficient that the top of the wood

frame retaining the aggregate will be at trail grade. The width of the landing shall be equal to the designed width of the trail steps. The aggregate landing shall be framed in with 4” x 8” construction heart redwood, cedar, or pressure treated Douglas fir. Where the framing members join they shall be notched with a lap joint and pinned with 5/8” x 24” rebar or ¾” pipe 24” long. A pilot hole for the rebar or pipe shall be 1/16” smaller than the diameter of the rebar or pipe. The backfill placed within the wooden frame shall be 1 ½” minus crushed aggregate. The aggregate backfill shall have a minimum depth of 8” and be placed and compacted in maximum 3” lifts. Unit of payment is based on number of aggregate landings constructed. (Refer to the Harden Trail Approach drawing in specification diagram.)

Local Rock Manufacturing and Gathering

The rock necessary for the various rock structures shall be split and gathered onsite from materials exposed during trail excavations or from adjacent slopes designated by the state’s representative. Unit of payment for rock splitting is based on cubic foot of rock produced and payment varies by hardness of rock.

Local Rock Hauling

Rock hauled from the gathering/quarry site to the worksite may require the use of wheel barrows or motorized toters. Unit of payment shall be based on cubic feet of rock hauled, the method of transportation and the distanced the rock is hauled.

Rock Imported From Trailhead

Rock hauled from the trailhead to the worksite may require the use of wheel barrows or motorized toters. Unit of payment shall be based on cubic feet of rock hauled, the method of transportation and the distanced the rock is hauled.

Abutment Construction Wood/Plastic Wood Crib

Wood cribbed abutments begin with the excavation of a foundation. The foundation shall be excavated into stable mineral soil and be level. Each course of a wood crib abutment shall consist of facers, wings and anchor post. Each wall course shall be interlocked through the use of notching and be notched so that there is a one inch gap between each facer and wing course. The anchor post shall be notched so that it is installed at a 10% downward angle and interlocked with another anchor post in the interior of the abutment or shall extend from one wall face to another and be notched into both faces. The notching shall be performed so that the faces of all interlocking members fit tightly together and have uniform contact where the notches join together each structural member.

On any course, the anchor post shall not be spaced more than 8 feet apart horizontally. Where the length of the facer or wing wall is such that two or more facers or wings are spliced together, the splice shall be a lap joint. Splices in the facer and wings in the next course of the wall shall be staggered so that these joints do not occur consecutively. Anchor posts shall be placed on each side of the splice to provide additional support for

39 these joints. Anchor post shall also be installed so they are staggered and not placed directly above the preceding course. When joining the facer and wing walls together, the ends of the facer and wing wall members shall extend beyond the notch a minimum of 6 inches to help lock the two members together. Anchor post ends shall also extend a minimum of 6 inches beyond the notch. As directed by the contract’s representative, all wing, facer and anchor post should be either all heart redwood, cedar, pressure treated Douglas Fir, wood/plastic composite or recycled plastic wood and should be a minimum of 12 inches thick and a minimum of 12 inches wide or high (if using logs, the minimum all heart diameter will be 12 inches at the small end.

Upon the completion of each multi tier course, the area behind the wall shall be backfilled. Backfill material shall be of sufficient size that it will not sift out between the gaps in the wall. Backfill will consist of permeable aggregate soils or drain rock to promote drainage and reduce pore pressure. Rocks larger than 4 inches shall not be used as backfill material. Unit of payment is based on square feet of retaining wall constructed. This is calculated by measuring the square footage of the facers and wings. (Refer to cribbed abutment drawings in specification diagrams.)

Concrete Abutment Construction

As per the concrete abutment plans, this work includes fabricating and installing form boards (including she bolts, bridge washers and snap ties), installing required reinforcement steel, wire and fiberglass mesh, mixing and pouring the concrete, finishing the concrete, installing the required bridge hardware and striping and hauling away the form boards when the concrete is properly cured. Unit of payment for forming shall be measured by total square feet of abutment surfaces and the unit of measurement for pouring of concrete shall be by cubic feet of concrete poured. (Refer to concrete abutment drawings in specification diagrams).

Abutment Construction Wood Trestle (Mid Span Support)

Trestles require a strong and stable foundation. A concrete sill serves as its foundation. The slab is formed and poured on level and compacted mineral soil or rock. The concrete slab shall be a minimum of 1’ longer than the mud sill (mud sill length varies depending on the height of the trestle). It shall be a minimum of 2’ wide for a single trestle and 4’ wide for double trestle. The slab shall have a minimum thickness or depth of 1’. For additional structural strength, the slab should be reinforced with 5/8” rebar. Galvanized 1” J bolts are inset into the concrete slab. These bolts anchor the galvanized or stainless steel metal brackets used to secure the mud sill to the concrete slab. The trestle shall be constructed of con-heart grade redwood, Alaskan yellow cedar or pressure treated Douglas fir. The trestle consists of three components: the mud sill, the columns and the trestle sill. If single free span of the bridge exceeds 32 feet, a double trestle shall be used to distribute the additional load weight. The outside support columns should connect to the mudsill at a 78 degree angle. The top, outside edge of each column should line up with the outside edge of the stringers. The bottom, outside edge of the columns should be a minimum of 8 inches from the end of the mudsill. The minimum end dimensions of the mudsill should be 14 x 14 inches. The length of the

40 mudsill will vary depending on the height of the trestle but should be a minimum of 8 feet to provide adequate stability and load-bearing surface area. For every 1 foot increase in the height of the trestle (measured from the top of the mudsill to the bottom of the trestle sill), the distance between the outside support columns needs to be increased by 6 inches The outside support columns’ end dimensions should be a minimum of 8 x 12 inches. If the height of the trestle (measured from the top of the mudsill to the bottom of the trestle sill) is greater than 3 feet, a third 8 x 14-inch center support column is placed in the middle. To attach the columns to the mudsill, metal brackets are bolted to the mudsill with 5/8- x 10-inch galvanized lag screws and the columns are through bolted to the brackets with 5/8- x 10-inch galvanized hex headed bolts. The outside support columns attach to the trestle sill directly beneath the stringers and extend downward at an angle of 12 degrees outward from vertical, giving the structure an inverted “V” shape. This angle lends stability to the structure. The trestle sill should have minimum end dimensions of 12 x 14 inches with a length not exceeding the length of the mudsill. To attach the columns to the trestle sill, metal brackets are bolted to the trestle sill with 5/8- x 10-inch galvanized hex headed bolts and the columns are through bolted to the brackets with 5/8- x 10-inch galvanized hex headed bolts.

The trestle sill must be installed square and level to the trestle sill(s) supporting the opposite end of the bridge stringers. The bridge stringers should be attached to the trestle sill via galvanized or stainless steel brackets and through-bolted. If the trestle is joining two spans with stringers of different dimensions, fabricated metal supports may be placed beneath the smaller stringers to bring them level to the top of the larger stringers. The trestle sills should be centered over the mudsill with respect to both length and width. Cross bracing with a minimum dimension of 4 x 8 inches should be attached to both sides of the trestle to prevent rocking. The cross braces should extend diagonally from the top of the trestle sill to the bottom of the opposite mudsill. The cross bracing is fastened to the mudsill and trestle sill with 5/8- x 20-inch galvanized hex headed bolts. Cross braces are installed so they join the mudsills and trestle sills at approximately the same location on the outermost support columns. If both sides are cross braced, the cross braces will run in opposite directions. Where possible, cross braces should be fastened to the center support columns as well. When two trestles are used, cross bracing should be installed to join them. In this instance, cross bracing is fastened to the top of the outside support column of one trestle and to the bottom of the outside support column on the other trestle. Both sets of outside support columns should be cross braced, with braces running in opposite directions. Unit of payment for forming shall be measured by total square feet of abutment surfaces and the unit of measurement for pouring of concrete shall be by cubic feet of concrete poured. Unit of payment for fabrication and assembly of trestle shall be by individual trestle, type (single or double) and height (lineal foot of trestle) constructed. (Refer to wood trestle drawings (single and double) in specification diagrams).

Bridge Construction

The BMPs designated by the contract’s representative shall be installed prior to construction activities. Following the plans provided by the contract representative constructing standard log stringer, milled wood, wood overhead truss, wood hip truss,

41 wood Gluelam, all weather steel I beam, galvanized steel I beam, steel truss, aluminum truss, fiber reinforced I beam or fiber reinforced pony hiking bridges includes securing stringers to the abutments so that they are level, squared to each other and plumb with the camber on top using the hardware designated by the contract’s representative. It also includes installing diaphragms and tensioning rods or bridging to unitize and stiffen the bridge stringers. Soil dams (if not included in the abutment design) shall be installed between the bridge stringers and the surrounding soils. The top of the soil dams shall be level with the bridge decking and trail tread. Installing post sills and post braces if designated by the contract’s representative so that they are level and plumb and fit flush against adjoining structural members without gaps in excess of 1/32”. Post shall be installed so they are plumb and match the height and spacing designated by the state’s representative. The decking shall be installed to overhang the outside of the stringers a minimum of 5” and be perpendicular to the stringers and has the spacing or gaps between decking boards designated by the state’s representative. They shall be fastened as per the manufactures instructions. All decking boards shall have pre drilled pilot holes appropriately sized to the fastener being used. All decking fasteners shall be installed so they are set flush or slightly below the surface of the decking. The top handrails shall be installed so that they are level and plumb and fit flush against adjoining structural members without gaps in excess of 1/32”. The top of the completed handrail will be 42 inches above trail tread level for mountain biking and pedestrian hiking trails, 54 inches for equestrian trails and 32 - 51 inches above the tread for accessible trails. Standard dimensions for handrails shall be a minimum of 4 inches x 6 inches. Splices in rails shall be made at an upright post to assure a firm splice. The top rail shall be notched to a depth of one inch over the post and be fixed to the upright posts with #40 galvanized nails. All nail attachments shall have a predrilled pilot hole. A minimum of four nails shall be used to attach each end of a railing to a post. The diagonal rail shall be cut flush at the appropriate angle for a tight fit against the upright posts and fastened to the posts with #40 galvanized nails. Diagonal rails shall fit flush against adjoining structural members without gaps in excess of 1/32”. This work shall also include sanding post and rails to a smooth finish. All BMPS installed and associated debris shall be removed. Unit cost is based on type of bridge and lineal feet of bridge constructed. (Refer to bridge construction drawings in the specification diagrams.)

Hand Transport Bridge Materials

Work includes hand packing or transporting bridge materials via a trail cart, toters, bridge stringer dollies, rigging or some other mechanical means of transportation. This includes but is not limited to bridge sills, stringers, post sills, post braces, diaphragms, tension rods, bridging, post, railing, decking, soil dam lumber and all associated fasteners and hardware. Payment is based upon the number of hours times the number of people required to carry materials from the nearest trailhead to the bridge construction site. Due to variations in the time required due to terrain, distances and the size of bridge materials, this payment shall be a reflection of the actual hours required.

Timber Planking Construction

Following the layout for timber planking structures provided by the contract’s representative, construction of a timber planking structure begins by excavating and leveling the foundations for the log or sawn timber sills. Where soil conditions allow, the earthen foundations for the sills should be level front to back and side to side. The sill foundations should also be level to each other to avoid uneven loading of the structure. In fens with tussocks or in dense tundra mat, precise leveling and squaring of the sills may not be possible. Excavation may also need to be kept to a minimum to reduce disturbance to vegetation and permafrost. The builder needs to make the sills as level and square as the site conditions allow. The sills should be comprised of the most rot- resistant tree species available, such as redwood or cedar. The bark and sapwood should be removed from the sill logs to reduce rot and increase their lifespan. The diameter and length of the sills will be determined by the strength of the underlying soil and the intended width of the planking. The sill will also need sufficient height to provide an air gap between the wooden planks and the surrounding soil. The maximum distance between two sills should not exceed 8 feet. The top of the sills should also be level to provide a flat surface that the planks can fully rest upon. If power tools are permissible, a portable saw mill, chainsaw, or a chainsaw with a power plane attachment can be used to perform this task. If they are not allowed, then a beveled hatchet, adze, draw knife, slick, or wood chisel can be used to level the tops of the sills. Prior to anchoring the sills they should be pre-drilled with two 9/16-inch diameter pilot holes on either end of the log. A 5/8-inch piece of rebar is then driven through each hole to pin the sill log to the ground. The length of the rebar should be sufficient to have it penetrate through the sill and into the ground a minimum of 30 inches. If the underlying soil is subject to severe freeze-thaw or frost-heave conditions then do not pin the sills. Pinning will not allow the timber planking structure to freely move with the undulating ground. Once the sills are anchored, the planking is installed. These planks should be a minimum of 4 x 12 inches in dimension and have a maximum free span of 8 feet. They should also be constructed of rot resistant wood, such as redwood or cedar. If constructed of native materials they will either be rough sawn (using a portable saw mill) or hand split using splitting wedges. The planking can be installed either as a single plank or two planks side by side. If an individual timber plank structure is being constructed, the plank should be installed so that the ends are flush with the outside edge of the starting and ending sills. With a multiple timber plank structure, the ends of the first planks are placed flush with the outside edge of the beginning sill and approximately halfway on (or center of) the next or second sill. The next set of planks will butt against the first planks and rest halfway on the second sill and halfway on the third sill. The planks should be fastened to the sills by drilling a 5/16-inch pilot hole through the planking and driving in 7-inch galvanized spikes or 7-inch timber lock screws until they are flush with the planking’s surface. A punch or drift pin should then be used to recess the heads of the nails a minimum 1/8-inch below the surface of the planking. A minimum of six nails or screws should be used for each piece of planking (three on each end of the planking). The two outside nails are located approximately 1 1/2 inches in from the edge of the planking. Where multiple timber planking sections are constructed and the planking is laid out and constructed to curve with the terrain the ends of the planking must be cut at an angle. The angle will vary depending on the amount of curve desired. Once the

planks have been cut, the sills are set to match the angle of the end cuts on the planking. Unit of payment is based on type of timber planking constructed (single or double) and lineal feet of timber planking constructed. (Refer to timber planking construction drawings in the specification diagrams.)

Puncheon Construction

Following the layout for puncheon structures provided by the contract’s representative, construction of a puncheon structure shall begin by excavating and leveling the mud sill foundations. The mudsills should be a minimum of 6 feet long, 10- x 10-inch con heart redwood, cedar, or pressure treated Douglas fir. If the native soil is weak and unconsolidated, the length of the mudsills may need to be increased to 8 feet. The mudsills are anchored to the native soil by drilling a 9/16-inch hole approximately 6 inches from each end of the mudsill. These holes should be drilled prior to laying the mudsill on the ground so the auger bit does not come into contact with the soil. The holes are centered on the mudsill. Then a 5/8-inch x 3-foot piece of rebar is driven through the holes and into the ground so that the top of the rebar is flush with the top of the mudsill. Once the mudsills are placed, the joists are installed. There should be a minimum of two 6- x 8-inch select structural Douglas fir joists attached to the top of the mudsills. The joists should be squared to the mudsills, centered, and spaced so the two outside joists are 48 inches apart (outside to outside) for a puncheon without bull rails. The joist spacing should be 60 inches if bull rails are installed. The maximum free span of these joists should be 12 feet. To layout the joists, measure the length of the mudsill and divide that number in half. Then measure that distance from one end of the mudsill and scribe a line from top to bottom across the mudsill. This line is the center of the mudsill. From that line measure 24 inches toward the end of the mudsill in both directions; then scribe lines from top to bottom across the mudsill at those locations. These two lines represent the outside edges of the joists. Note if bull rails are to be installed, measure 30 inches in both directions to scribe the top to bottom lines. The joists should be fixed to the mudsills by pre-drilling the joist with a 3/8-inch diameter pilot hole and driving a 12-inch galvanized spike through the joist and into the mudsill. Once the joists are pinned, the decking can be installed. The decking material should be 3 inches thick and a minimum of 60 inches long if there are no bull rails and 72 inches long if there are bull rails. The decking should be installed to overhang the outside of the stringers by a minimum of 5 to 7 inches and be perpendicular to the stringers. When laying the decking down, a rough or irregular edge to the decking is to be achieved by altering the overhang length of every other piece of decking. Unless the climate is cool and moist most of the year, a space of 1/4 to 3/8 inches should be left between the decking boards to allow for swelling and shrinking of the decking boards. In a very hot and dry desert climate, board shrinkage can be substantial. In these conditions, the decking should be installed without a gap; otherwise the gap may become too wide, especially by accessible trail standards. Note, when installing decking it is important that the boards are laid with the crowned side up. Using the center of the joist as a guide, a chalk line can be snapped across the top of the decking to provide a reference for nailing. The decking should be fastened to the joist by drilling a 7/32-inch pilot hole through the decking and into the stringer. The depth of the pilot hole should leave at least 1 1/2 to 2 inches of un-drilled wood in the joist to firmly grasp the fastener. When

44 using long decking screws (5 to 6 inches), it may be necessary to drill the holes deeper because screws this long shear easily. When the decking wood is hard and dry it may also be necessary to lubricate the nails or screws to install them. With 3-inch decking, drive in 60D galvanized nails until they are flush with the decking surface. A punch or drift pin should then be used to recess the head of the nails a minimum 1/8-inch below the surface of the decking. Stainless steel deck screws 6 inches long can also be used to fasten the decking to the joist. If the decking used is 6 inches wide or less, then two fasteners are used per board. These fasteners should be placed approximately 1 1/2 inches from the edge of the boards to keep the boards from curling or cupping. If the boards are wider than 6 inches, then three fasteners per board are used; two approximately 1 1/2 inches from the edge of the board and one in the center. If hand split decking is used then an adze should be used to level the decking. If power tools can be used, then a chainsaw with a power plane attachment can be used to quickly level the decking’s surface. Prior to leveling the decking, make sure the nail heads are well below the depth of wood that needs to be removed. Leveling should be sufficient so there are no vertical rises in the decking’s surface in excess of 1/4 inch. Once the decking is down and secured, the soil dams are installed. The soil dams are attached to each end of the puncheon to provide separation between the puncheon structure and the surrounding soil. They should be con heart redwood, cedar, or pressure treated Douglas fir. The soil dams should be a minimum dimension of 3 inches thick and the same length as the mudsills. The number of boards will be dictated by the overall height of the puncheon. The soil dam should span from the bottom of the mudsill to the top of the decking. It is fastened to the ends of the joist and the mudsill. Pilot holes should be pre-drilled to facilitate nailing the soil dam to the joist and mudsill. A pre-drilled soil dam board is then placed against the end of the puncheon so that the top of the board is flush with the top of the decking board. A line marking the center of the soil dam board should line up with a line scribed on the center of the mudsill. While holding the soil dam board in place, use nails to fasten it to the ends of the joist and/or mudsill. Galvanized 60d nails are used to fasten the soil dam boards. Once the top soil dam board is installed, the second soil dam is installed following the same process. Depending on the overall height of the puncheon, the second 12-inch soil dam board may need to be ripped to fit in the remaining space or the soil in front of the mudsill can be excavated to provide the space to accommodate a 12 inch wide board. Once the soil dams are installed, the area between the soil dams and the existing trail tread should be filled with the prescribed tread material and compacted in maximum 3-inch lifts. The finished trail grade should be flush with the top of the decking. If the puncheon is for an accessible trail, bull rails can be attached to the outside edge of the decking to provide edge protection. To provide a 5-foot wide deck between the bull rails, the puncheon joists must be spaced 60 inches apart (outside to outside measurement), instead of the standard 48 inches. Once the decking is installed, snap a string line across the top of the decking boards. The string line should be aligned with the outside edge of the joists. The bull rail will be attached to the decking on the outside of this caulk line. The bull rail should be redwood, cedar, pressure treated Douglas fir, or plastic wood. The bull rail is attached to the decking by placing 2- x 4-inch wooden or plastic lumber blocks between the bull rail and decking. These blocks are required to elevate the bull rail off of the decking to allow water to drain and reduce the buildup of organic material that will

increase rot. These blocks should be inset from the ends of the bull rail by approximately 2 inches and have a maximum spacing of 48 inches.

The bull rail should be a minimum of 4 x 4 inches with 4 x 6 inches preferred. Once the blocks have been properly spaced and the bull rails laid on top of them, clamp the bull rail to the decking to keep the blocks and bull rails fixed until they can be anchored. The bull rails and blocking are attached to the decking by drilling a 3/8-inch hole through the rail, bock, and decking, and fastening all three together with 3/8- x 12-inch galvanized carriage bolts. This design should provide a minimum decking width of 60 inches between the bull rails and a minimum 2- inch gap between the decking and the bull rails. Unit of payment is based on lineal feet of puncheon constructed. (Refer to puncheon construction drawings in the specification diagrams. If the puncheon is for an accessible trail, bull rails can be attached to the outside edge of the decking to provide edge protection. To provide a 5-foot wide deck between the bull rails, the puncheon joists must be spaced 60 inches apart (outside to outside measurement), instead of the standard 48 inches. Once the decking is installed, snap a string line across the top of the decking boards. The string line should be aligned with the outside edge of the joists. The bull rail will be attached to the decking on the outside of this caulk line. The bull rail should be redwood, cedar, pressure treated Douglas fir, or plastic wood. The bull rail is attached to the decking by placing 2- x 4-inch wooden or plastic lumber blocks between the bull rail and decking. These blocks are required to elevate the bull rail off of the decking to allow water to drain and reduce the buildup of organic material that will increase rot. These blocks should be inset from the ends of the bull rail by approximately 2 inches and have a maximum spacing of 48 inches. The bull rail should be a minimum of 4 x 4 inches with 4 x 6 inches preferred. Once the blocks have been properly spaced and the bull rails laid on top of them, clamp the bull rail to the decking to keep the blocks and bull rails fixed until they can be anchored. The bull rails and blocking are attached to the decking by drilling a 3/8-inch hole through the rail, bock, and decking, and fastening all three together with 3/8- x 12-inch galvanized carriage bolts. This design should provide a minimum decking width of 60 inches between the bull rails and a minimum 2-inch gap between the decking and the bull rails.

Unit of payment is based on lineal feet of puncheon constructed. (Refer to puncheon construction drawings in the specification diagrams.)

Equestrian Puncheon Construction

Following the layout for puncheon structures provided by the contract’s representative, construction equestrian puncheon structure shall begin by excavating and leveling the mud sill foundations. The mudsills should be a minimum of 6 feet long, 10- x 10-inch con heart redwood, cedar, or pressure treated Douglas fir. If the native soil is weak and unconsolidated, the length of the mudsills may need to be increased to 8 feet. The mudsills are anchored to the native soil by drilling a 9/16-inch hole approximately 6 inches from each end of the mudsill. These holes should be drilled prior to laying the mudsill on the ground so the auger bit does not come into contact with the soil. The holes are centered on the mudsill. Then a 5/8-inch x 3-foot piece of rebar is driven through the holes and into the ground so that the top of the rebar is flush with the top of

46 the mudsill. Once the mudsills are placed, the joists are installed. There should be a minimum of three 6- x 8-inch select structural Douglas fir joists attached to the top of the mudsills. The joists should be squared to the mudsills, centered, and spaced so the two outside joists are 60 inches apart (outside to outside) for a puncheon with bull rails. The maximum free span of these joists should be 12 feet. To layout the joists, measure the length of the mudsill and divide that number in half. Then measure that distance from one end of the mudsill and scribe a line from top to bottom across the mudsill. This line is the center of the mudsill. From that line measure 30 inches toward the end of the mudsill in both directions; then scribe lines from top to bottom across the mudsill at those locations. These two lines represent the outside edges of the joists. The joists should be fixed to the mudsills by pre-drilling the joist with a 3/8-inch diameter pilot hole and driving a 12-inch galvanized spike through the joist and into the mudsill. Once the joists are pinned, the decking can be installed. The decking material should be 4 inches thick and a minimum of 72 inches long. The decking should be installed to overhang the outside of the stringers by a minimum of 5 to 7 inches and be perpendicular to the stringers. When laying the decking down, a rough or irregular edge to the decking is to be achieved by altering the overhang length of every other piece of decking. Unless the climate is cool and moist most of the year, a space of 1/4 to 3/8 inches should be left between the decking boards to allow for swelling and shrinking of the decking boards. In a very hot and dry desert climate, board shrinkage can be substantial. In these conditions, the decking should be installed without a gap; otherwise the gap may become too wide. Note, when installing decking it is important that the boards are laid with the crowned side up. Using the center of the joist as a guide, a chalk line can be snapped across the top of the decking to provide a reference for nailing.

The decking should be fastened to the joist by drilling a 5/16-inch pilot hole through the decking and into the stringer. The depth of the pilot hole should leave at least 1 1/2 to 2 inches of un-drilled wood in the joist to firmly grasp the fastener. When the decking wood is hard and dry it may also be necessary to lubricate the nails to install them. With 4-inch decking, drive in 7” galvanized spikes until they are flush with the decking surface. A punch or drift pin should then be used to recess the head of the nails a minimum 1/8-inch below the surface of the decking. If the decking used is 6 inches wide or less, then two fasteners are used per board. These fasteners should be placed approximately 1 1/2 inches from the edge of the boards to keep the boards from curling or cupping. If the boards are wider than 6 inches, then three fasteners per board are used; two approximately 1 1/2 inches from the edge of the board and one in the center. If hand split decking is used then an adze should be used to level the decking. If power tools can be used, then a chainsaw with a power plane attachment can be used to quickly level the decking’s surface. Prior to leveling the decking, make sure the nail heads are well below the depth of wood that needs to be removed. Leveling should be sufficient so there are no vertical rises in the decking’s surface in excess of 1/4 inch. Once the decking is down and secured, the soil dams are installed. The soil dams are attached to each end of the puncheon to provide separation between the puncheon structure and the surrounding soil. They should be con heart redwood, cedar, or pressure treated Douglas fir. The soil dams should be a minimum dimension of 3 inches thick and the same length as the mudsills. The number of boards will be dictated by the overall height of the puncheon. The soil dam should span from the bottom of the mudsill 47

to the top of the decking. It is fastened to the ends of the joist and the mudsill. Pilot holes should be pre-drilled to facilitate nailing the soil dam to the joist and mudsill. A pre-drilled soil dam board is then placed against the end of the puncheon so that the top of the board is flush with the top of the decking board. A line marking the center of the soil dam board should line up with a line scribed on the center of the mudsill. While holding the soil dam board in place, use nails to fasten it to the ends of the joist and/or mudsill. Galvanized 60d nails are used to fasten the soil dam boards. Once the top soil dam board is installed, the second soil dam is installed following the same process. Depending on the overall height of the puncheon, the second 12-inch soil dam board may need to be ripped to fit in the remaining space or the soil in front of the mudsill can be excavated to provide the space to accommodate a 12 inch wide board. Once the soil dams are installed, the area between the soil dams and the existing trail tread should be filled with the prescribed tread material and compacted in maximum 3-inch lifts. The finished trail grade should be flush with the top of the decking. Bull rails are attached to the outside edge of the decking to provide edge protection. Once the decking is installed, snap a string line across the top of the decking boards. The string line should be aligned with the outside edge of the joists. The bull rail will be attached to the decking on the outside of this caulk line. The bull rail should be redwood, cedar, pressure treated Douglas fir, or plastic wood. The bull rail is attached to the decking by placing 2- x 4-inch wooden or plastic lumber blocks between the bull rail and decking. These blocks are required to elevate the bull rail off of the decking to allow water to drain and reduce the buildup of organic material that will increase rot. These blocks should be inset from the ends of the bull rail by approximately 2 inches and have a maximum spacing of 48 inches. The bull rail should be a minimum of 4 x 8 inches. Once the blocks have been properly spaced and the bull rails laid on top of them, clamp the bull rail to the decking to keep the blocks and bull rails fixed until they can be anchored. The bull rails and blocking are attached to the decking by drilling a 3/8-inch hole through the rail, bock, and decking, and fastening all three together with 3/8- x 15-inch galvanized carriage bolts. This design should provide a minimum decking width of 60 inches between the bull rails and a minimum 2-inch gap between the decking and the bull rails. Unit of payment is based on lineal feet of equestrian puncheon constructed. (Refer to equestrian puncheon construction drawings in the specification diagrams.

Boardwalk Construction

Following the layout for boardwalk structures provided by the contract’s representative, construction of a boardwalk structure shall begin by excavating and leveling the mud sill, pier block, diamond pier or helical anchor foundations by using batter boards, auto level and string lines. If mud sills are used, they shall be recycled plastic wood or pressure treated Douglas fir. They shall have minimum dimensions of 10” X 10” X 6 feet long. If the native soils are weak and unconsolidated the sill’s length shall be increased to a minimum of 8’. The mud sills, pier blocks, diamond piers or helical anchors shall be level and squared to each other unless the boardwalk is to be curved in which case they shall be level but flared to each other to establish the desired curve. The number of joist shall be determined by the contract’s representative and the materials used. The joist shall adhere to the prescribed layout, be spaced equally apart and be 50” apart outside to outside. The maximum span of these joists shall be 12 feet. The joists shall be fixed

to the sills, pier blocks, diamond piers or helical anchors by following the contract representative instructions. The decking material shall be a minimum of 5 feet long and 3 inches thick. The decking shall be installed to overhang the outside of the joist by 5” and be perpendicular to the joist. They shall be fastened to the joist by following the contract representative instructions. All decking boards shall have pre drilled pilot holes appropriately sized to the fastener being used. All decking fasteners shall be installed so they are set flush or slightly below the surface of the decking. A soil dam of con heart redwood, cedar or pressure treated Douglas fir shall be attached to each end of the boardwalk structure. The top of the soil dam shall be level with the top of the decking. The area between the soil dam and the existing trail tread shall be filled with the prescribed tread material and compacted in 3” lifts. The finished trail grade shall be flush with the walking surface of the boardwalk. If the boardwalk structure is installed on an accessible trail then bull rails shall be attached to the outside edge of the decking to provide edge protection. The bull rail shall be redwood, cedar, pressure treated Douglas fir or plastic wood. The bull rail is attached to the decking by placing 2” x 4” x 4” wooden or plastic lumber blocks between the bull rail and the decking. These blocks shall be inset from the ends of the bull rail approximately 2” and have a maximum spacing of 48”. The bull rail shall be a minimum of 4” x 4” with 4” x 6” stock preferable. The bull rails and blocking are attached to the decking by drilling a 3/8” hole through the rail, bock and decking and fastening all three together with 3/8” x 12” galvanized carriage bolts. If handrails are required, the top handrails shall be installed so that they are level and plumb and fit flush against adjoining structural members without gaps in excess of 1/32”. The top of the completed handrail will be 42 inches above trail tread level for mountain biking and pedestrian hiking trails and 32 - 51 inches above the tread for accessible trails. Standard dimensions for handrails shall be a minimum of 4 inches x 6 inches. Splices in rails shall be made at an upright post to assure a firm splice. The top rail shall be notched to a depth of one inch over the post and be fixed to the upright posts with #40 galvanized nails. All nail attachments shall have a predrilled pilot hole. A minimum of four nails shall be used to attach each end of a railing to a post. The diagonal rail shall be cut flush at the appropriate angle for a tight fit against the upright posts and fastened to the posts with #40 galvanized nails. Diagonal rails shall fit flush against adjoining structural members without gaps in excess of 1/32”. This work shall also include sanding post and rails to a smooth finish. Unit of payment is based on type of boardwalk constructed (wood mud sill and joist, plastic mud sill and joist, post and pier block, diamond pier or helical anchor) and lineal feet of boardwalk constructed. (Refer to boardwalk construction drawings in the specification diagrams.)

Wood Safety Railing Construction

Wood safety railings shall be constructed by installing in the ground upright wooden posts, 4” x 6” minimum, set in the ground a minimum of 24 inches, set 8 feet to 10 feet apart and spanned by 2 rails. An alternate method of post installation is using a fabricated steel post bracket anchored in an 18” x 18” x 18” concrete footing. Material for standard railing designs shall be of select heart 4” x 6” redwood or cedar. The top of the completed handrail will be 42 inches above trail tread level for mountain biking and pedestrian hiking trails 54 inches for equestrian trails and 32 - 51 inches above the ground for accessible trails.

Splices in rails shall be made at an upright post to assure a firm splice. The top handrails shall be installed so that they fit flush against adjoining structural members without gaps in excess of 1/32”.The top rail shall be notched to a depth of one inch over the post and be fixed to the upright posts with #40 galvanized nails. All nail attachments shall have a predrilled pilot hole. A minimum of four nails shall be used to attach each end of a railing to a post. The diagonal rail shall be cut flush at the appropriate angle for a tight fit against the upright posts and fastened to the posts with #40 galvanized nails. Diagonal rails shall fit flush against adjoining structural members without gaps in excess of 1/32”. Unit of payment is based on lineal feet of wood safety railing constructed. (Refer to wood safety railing construction drawings in the specification diagrams.)

Wood Safety Railing with Post Sills Construction

Wood railings with post sills shall be constructed by excavating a footing for the post sill that is perpendicular to the trail alignment. The footing shall extend from the inboard hinge to the outboard hinge of the trail bed. The footing is a minimum of 20 inches deep and 12 inches wide. The bottom of the footing must be in undisturbed mineral soil and level in all directions. Prior to placing the sill into the trench, two ½” pilot holes shall be drilled through the 6” x 8” sill, on center and approximately 12” in from the inboard and outboard hinges. When the sill is placed into the footing it shall be checked with a level to insure that it is level front to back and side to side. Once the sill is firmly secured into the footing, it shall be pinned in the footing with 5/8” x 30” to 40” rebar. The length of the sill depends on the designed trail width. The sill must extend beyond the outside edge of the trail sufficiently to install a post brace at a 45-degree angle. The 4- x 6-inch post is attached to the sill by toe nailing it into the sill with 30d galvanized nails. The bottom of the post shall make full contact with the post sill and the post shall be plumb. A post brace is then installed to support the post. The 4- x 6-inch brace is installed at a 45- degree angle and must be long enough to span from the end of the post sill to half way up the post. The cuts shall fit flat and flush against the post sill and post without gaps in excess of 1/32”. The post brace is toe nailed into the sill and post with 30d galvanized nails. A 3- x 12- x 20-inch soil dam is installed in the footing, up against the post. It is notched around the post sill and is the same width as the 12-inch footing. This soil dam is required to contain the backfill material placed on top of the sill. It is nailed to the post and toe nailed into the sill with 30d galvanized nails. Once the soil dam is installed, the footing is backfilled with crushed aggregate in compacted 3-inch lifts until the final grade and cross slope matches the desired trail tread. The post sills shall be set a maximum of ten feet apart. The post shall be spanned by 2 rails. Material for standard railing designs shall be of select heart 4 inches x 6 inches redwood or cedar. The top of the completed top railing will be 42 inches above trail tread level for mountain biking and pedestrian hiking trails, 54 inches for equestrian trails and 32 - 51 inches above the tread for accessible trails. Splices in rails shall be made at an upright post to assure a firm splice. The top rails shall be installed so that they fit flush against adjoining post without gaps in excess of 1/32”.The top rail shall be notched to a depth of one inch over the post and be fixed to the upright posts with #40 galvanized nails. All nail attachments shall have a predrilled pilot hole. A minimum of four nails shall be used to attach each end of a railing to a post. The diagonal rail shall be cut flush at the appropriate angle for

50 a tight fit against the upright posts and fastened to the posts with #40 galvanized nails. Diagonal rails shall fit flush against adjoining posts without gaps in excess of 1/32”. Unit of payment is based on lineal feet of wood safety railing constructed. (Refer to wood safety railing with post sills construction drawings in the specification diagrams.)

Split Railing Fence Construction

This work includes the excavation of post holes for the upright post used to contain the split rails. The post holes shall be a minimum of 24 inches deep and the post shall be a minimum of 4”x 6”x 6’ in dimension. The rails shall be a minimum of 4”x 6”x 12’ in dimension. The post and rails shall be either split redwood or cedar and shall be free of sapwood. The two support post shall be installed approximately 4” to 5” apart to receive the railings. Additional post shall be installed approximately 10’ apart to support the other end of the railing section. The initial railing course shall be a 4”x6”x12” redwood or cedar block which is placed between the two upright posts at ground level. This provides a soil moisture gap between the ground and the railing. A 6” high native rock is also acceptable. The first railing shall then be placed on top of the block or rock. If this is the end post of a split rail fence then another 4”x6”x12” wood block is placed on top of the railing. If it is part of a continuous fence then the railing from the adjacent segment is placed on top of the previous railing. If another railing is being used then that railing shall overlap the previous railing a minimum of 12”. This spacing or stagger is continued until four railings are installed between each post section. Once this is completed, the top of the two upright posts shall be wrapped and bound with 9 gauge galvanized wire to keep them from separating. Unit of payment is based on number of rails (high) and lineal feet of split rail fence constructed. (Refer to split rail fence construction drawings in the specification diagrams.)

Symbolic Fencing Installation

Symbolic fence post shall be a Hubbell 5/8” x 6’ galvanized steel anchor rod. The fence post shall be installed so that the height of the wire rope (when strung through the post eyelet) will be 42” off of the existing ground elevation. The post shall be installed on the outside edge of the trail bed no further than 30’ apart. The placement of the post shall conform to the trail alignment. The rope installed between the posts shall be galvanized 3/8” vinyl coated wire rope. It shall be secured to the post with 3/8” galvanized wire rope clips. Unit of payment is based on lineal feet of symbolic fencing constructed.

Soil Excavation

This work includes the removal of soil required to construct trail structures. Excavated soil shall be saved and used at a location designated by the contract’s representative. Levels of work vary depending on whether the soil is soft, medium, hard, comprised of slide debris and if hand labor or mechanized equipment is used. Unit of payment is by the cubic foot of soil excavated.

Rock Excavation

This work includes the removal of rock within the designed trail bed, travelway, or from excavations required to construct trail structures. Rock shall be removed from the trail bed so as to leave a smooth and uniform tread surface without holes, rock protrusions and concave depressions that can trap water. Soft and unconsolidated rock can usually be excavated with hand tools such as picks, rock bars, double jacks, and airless jack or slide hammers. Hard rock is usually excavated with gas powered jack hammers and or gas powered drills, plugs and feathers and expansion agents. A mini excavator with a hydraulic hammer attachment may be used to rough out the initial rock excavation. Excavated rock shall be saved and used at a location designated by the contract’s representative. Levels of work will vary depending on the hardness of the rock (soft, medium or hard) or if mechanized equipment or hand labor is used. Unit of payment is by the cubic foot of rock excavated.

Export Soil from Drainage

Work includes the excavation and exporting of soils from trail construction areas that are within the influence of drainages. This includes transporting soils to a designated storage or construction site outside the influence of the drainage. At the determination of the contract’s representative, this soil shall be used as backfill for trail structures if they are located within close proximity or shall be side cast at a location outside the influence of the drainage where it will not enter the water course. Unit of payment is based on cubic foot of soil hauled to the designated location, the distance the soil is hauled and the method of transportation is used.

Importing Fill Material

Work includes loading, transporting and installing fill material required for retaining walls, overlooks, landings, pads, etc. Fill material may consist of soil, aggregate or rock. Soil and aggregate shall be installed in maximum 3 inch lifts. Each lift shall be shaped and compacted per the contract representative’s instructions. Unit of payment is based on cubic feet of material hauled, the distance it is moved and the method of transportation used.

Work Performed Without Established Production Rates

This work includes all tasks performed on trail maintenance or construction projects where pre established production rates do not exist or apply. These categories of work shall be compensated for on an hourly payment basis. The hourly rate shall be the same compensation rate set for crew or specialized workers in the contract documents. The number of hours applied to these tasks shall be tracked by the contract’s representative and the contractor. These hours shall be reviewed, agreed upon, recorded and signed by the contract’s representative and contractor on a daily basis.

Step-Over Stiles

The step-over stile incorporates two vertical posts with a single rail. The posts are 10” in diameter and 7’ long. They are buried 3’ into the ground and placed 18 inches apart. The rail is 4” x 6” x 38” and is fastened between the posts at 18 inches above the trail grade. The posts are notched 1” so the rail fits flush against them. The rail is fastened to the post with four 3/8” x 8” lag screws (two per post). This stile provides an opening wide and low enough for a hiker to cross over, but too narrow and high for stock or off- road vehicles. The width may be altered to prohibit or allow bicycles. Compensation for installing these stiles shall be at the hourly unit rate established in the contract documents. (Refer to step- over stile construction drawings in the specification diagrams.)

Stair Step-Over Stiles

The stair step-over stile consists of two stringer stairways and a platform. The stairways are a minimum of 3 feet wide and connect to a platform that is a minimum of 3 feet above trail grade. The platform has a minimum size of 3 feet by 2 feet. Hikers can step up and over this barrier but stock and off-road vehicles cannot. This configuration is commonly used to cross a fence without modifying the existing fence line. Compensation for installing these stiles shall be at the hourly unit rate established in the contract documents. (Refer to stair step-over stile construction drawings in the specification diagrams.)

Pass-Through Stiles

Pass through stiles have posts that are placed 5 feet apart to provide an opening for users to pass. A log or “step-over” barrier is placed in front of the opening between the two posts. Three logs, 18 inches in diameter are placed parallel to the opening, with a 30-inch landing in between. They are placed 4 inches into the ground and anchored with pipe or rebar. Two additional logs are placed perpendicular to these logs, across the ends, and pinned 4 inches into the ground. All five logs have a finished height of 14 inches above trail grade. The 30-inch landing between the three front logs provides the spacing necessary for stock to step over. Similarly to wooden and rock steps, this spacing enables stock to have half of its body on a landing at a time. The tread for these landings consists of sand or a soft mix of soil and aggregate, which provides stock with sure, comfortable footing. Compensation for installing these stiles shall be at the hourly unit rate established in the contract documents. (Refer to pass-through stile construction drawings in the specification diagrams.)

Walk- Through Maze Stiles

The walk-through maze stile uses posts and rails installed closely together in a zigzag pattern. The close spacing 24” between the rails and the alternating zigzag pattern and short distance between the posts prevent cattle, horses, and vehicles from passing through this stile. Compensation for installing these stiles shall be at the hourly unit rate established in the contract documents. (Refer to walk-through maze stile construction drawings in the specification diagrams.)

Walk- Through Maze Chicane Stiles

The walk–through maze chicane stile is similar to the walk-through maze stile but wider to provide access for people using mobility assistive devices. The spacing between the rails is a minimum of 36” apart at the entrances and 42” at the turns. Compensation for installing these stiles shall be at the hourly unit rate established in the contract documents. (Refer to walk-through maze chicane stile construction drawings in the specification diagrams.)

Trailside and Trail Camp Amenities

This work includes the installation of all trailside or trail camp amenities identified in the contract or by the contract’s representative. Compensation for installing these amenities shall be at the hourly unit rate established in the contract documents for each of these amenities.

BMP Bridge Drop Cloth

After bridge stringers are placed and anchored, a geotextile fabric drop cloth is installed under the area where the bridge will be assembled. The drop cloth is installed to catch any debris that falls from the bridge as it is being assembled. The drop cloth spans from one abutment to the other and should be wide enough to extend beyond the outside of the finished bridge by 3 to 4 feet on each side.

The drop cloth can be anchored to wooden mudsills via nailing or pinned into the ground in front of non-wooden sills with U-shaped pieces of rebar. The drop cloth should hang far enough below the bridge stringers that it will not interfere with the installation of the post sills or cable truss assembly. The distance between the bottom of the bridge stringers and the water in the watercourse can also be a limiting factor in how low this drop cloth can be installed. If there is insufficient space to install the necessary bridge components, the drop cloth will have to be installed after they are attached to the stringers. Unit of payment is based on square feet of drop cloth installed.

BMP Coffer Dam

When constructing a culvert in a watercourse that has a very low volume of flow, a small coffer dam constructed of sand bags shall be installed above the culvert excavation limits to capture the stream flow. The water is then diverted around the culvert excavation area and back into the stream below the worksite through flexible plastic pipe to reduce turbidity and eliminate the saturation of the crossing fill as it is excavated. The sand bags shall be tightly fitted together and installed around the flexible pipe so minimal water passes through the dam. All excavated material from installing the coffer dam shall be exported to a stable location far enough away from the coffer dam site that it cannot re-enter the watercourse.

Once the coffer dam is no longer required, the soil behind it is carefully removed and taken to a location where it can be used as fill material or dispersed below the trail

54 alignment. The sand bags and flex pipe are removed and transported back to the shop or storage area. Unit of payment for sand bags is based on each bag installed. The unit of payment for the flex pipe is based on lineal feet of flex pipe installed. Payment for removal and relocation of soil is compensated for under soil export from drainage. (Refer to coffer dam construction drawings in the specification diagrams.)

BMP Silt Fencing

Silt fences are installed below soil disturbance or excavation areas where the soil may enter water courses below the worksite. They are installed with or without the wire fence backing. When installed where there is minimal soil catchment anticipated, the geotextile fabric can be attached with 9-gauge wires directly to the steel T posts. Where substantial soil catchment is anticipated the fence wire is installed to provide additional structural support to the silt fence. Once the silt fences are no longer required, the soil behind them is carefully removed and taken to a location where it can be used as fill material or dispersed below the trail alignment. Bare areas should be replanted with native vegetation and covered with organics to prevent erosion. The silt fences are removed and transported back to the shop or storage area. Unit of payment is based on lineal feet of silt fence installed. Payment for removal and relocation of soil is compensated for under soil export from drainage. Payment for revegetation is compensated for under site restoration for trail obliteration and narrowing level ground (Refer to silt fence construction drawings in the specification diagrams.)

BMP Straw Bales

Straw bales are installed below soil disturbance or excavation areas where the soil may enter water courses below the worksite. Straw bales are designed for low surface flows and can be installed on flat ground or a slope. They should always be installed perpendicular to the surface runoff (sheet flow). To keep water from running under the bale on sloping ground, a shallow footing shall be excavated to secure the bale. Once the straw bales are no longer required, the soil behind them is carefully removed and taken to a location where it can be used as fill material or dispersed below the trail alignment. Bare areas should be replanted with native vegetation and covered with organics to prevent erosion.

The straw bales are removed and transported back to the shop or storage area or can be used as mulch when restoring the worksite. Unit of payment is based on each straw bale installed. Payment for removal and relocation of soil is compensated for under soil export from drainage. Payment for revegetation is compensated for under site restoration for trail obliteration and narrowing level ground.

BMP Straw Wattles

Straw wattles are installed below soil disturbance or excavation areas where the soil may enter water courses below the worksite. Straw wattles are designed for low surface flows and can be installed on flat ground or a slope. They should always be installed perpendicular to the surface runoff (sheet flow). To keep water from running under the

55 wattle, a shallow trench with a depth of 3-5 inches, depending on the size of the wattle, is dug for the wattle to be laid. Wattles are secured to the ground with wooden stakes that are 18 inches long for 9-inch diameter wattles and 24 inches long for 12-inch diameter wattles. The stake is driven through the center of the wattle and perpendicular to the ground. Stakes are driven in at the end of each wattle as well as at 3- to 4-foot intervals for the rest of the length of the wattle. When installing wattles in a riparian area, willow cuttings can be substituted for wooden stakes to provide extra slope stabilization because their roots will help retain soil and their canopy will help protect the soil from rainfall impact. Once the straw wattles are no longer required, the soil behind them is carefully removed and taken to a location where it can be used as fill material or dispersed below the trail alignment. Bare areas should be replanted with native vegetation and covered with organics to prevent erosion.

The straw wattles are removed and transported back to the shop or storage area. Unit of payment is based on lineal feet of straw wattles installed. Payment for removal and relocation of soil is compensated for under soil export from drainage. Payment for revegetation is compensated for under site restoration for trail obliteration and narrowing level ground (Refer to straw wattle construction drawings in the specification diagrams.)

Spike Camp Operation Cost

This category includes compensation for setting up, operating and taking down a trail crew spike camp facility. The contractor shall be compensated one crew day each for the time required to set up and take down their spike camp facilities unless otherwise determined by the contract’s representative. The contractor shall also be compensated for the cost of operating and maintaining a spike camp facility. These costs include food, kitchen supplies, camp supplies, fuel, water, and repairs/maintenance to all the contractor’s camping equipment and materials. If a qualified contracted cook is supplied by the contractor to plan and prepare meals for their crew they shall be compensated for the cost of that cook. Unit of payment for spike camp setup and take down shall be the cost of one crew day each established in the contract documents. Unit of payment for spike camp operation cost shall be the weekly rate established in the contract documents. Unit of payment for the cook contract shall be the monthly rate established in the contract documents.

Vehicle Operation Cost

If the Government Contractor supplies vehicles to transport personnel or materials, tools and equipment and the cost of operating those vehicles is not included in the crew member hourly reimbursement rate those operation cost are reimbursed at the monthly vehicle operation rate established by the Department of General Services.

Hiking Travel Time

The average daily time spent on foot in transit to and from the work site. This time is measured from the nearest trailhead to the worksite. The unit of payment is the hourly reimbursement rate of the contractor for each hiking hour.

C1 / Crew Supervisor Overtime

If the Government Contractor (California Conservation Corps) is required to establish and operate out of a spike camp facility, additional compensation is provided for C1 overtime cost required to provide crew supervision during the crew’s days off. The rate of pay for this overtime shall be time and a half for a Conservationist 1.