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Wetland Trail Structures Weettllandand TTrailrail DDesignesign aandnd CConstructiononstruction 2007 EDITION Robert T. Steinholtz Bristlecone Trails, Lakewood, CO Brian Vachowski Project Leader USDA Forest Service Technology and Development Program Missoula, MT 8E82A3—Trail Treatment for Wet Areas January 2007 The Forest Service, United States Department of Agriculture (USDA), has developed this information for the guidance of its employees, its contractors, and its cooperating Federal and State agencies, and is not responsible for the interpretation or use of this information by anyone except its own employees. The use of trade, fi rm, or corporation names in this document is for the information and convenience of the reader, and does not constitute an endorsement by the Department of any product or service to the exclusion of others that may be suitable. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To fi le a complaint of discrimination, write to USDA, Director, Offi ce of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. i Acknowledgments ny document concerning trail construction must Christy Fischer was responsible for the initial editing of this recognize the men and women who do the fi eld work— manual. Thanks also to the staff at the USDA Forest Service Awhether they are professionals or volunteers. Some of Missoula Technology and Development Center (MTDC), the most unforgettable and fun-loving people we have known who obtained additional photographs, scanned fi gures, have worked on trail crews. provided review and additional content, and edited, laid out, and printed this document. In this revised edition, the None of the construction techniques in this document work involved Bert Lindler, Sunni Bradshaw, James “Scott” are new. Most have been used for decades. Fortunately, Groenier, and Jerry Taylor Wolf. Bob Steinholtz drew the trail crews took the time to explain and demonstrate the illustrations used throughout this manual. Thanks also to construction techniques to us. The techniques described in the U.S. Department of Transportation’s Recreational Trails this manual have occasionally been modifi ed slightly to make Program for funding the revision and additional distribution of it easier to work with contemporary materials. this manual. ii Contents Acknowledgments ________________________________ ii Introduction ______________________________________1 Types of Wetlands _________________________________2 Wetlands Formed by Glacial Action _________________________ 2 Wetlands With Organic Silt and Clay Soils ____________________ 2 Silt and Clay Soils With Some Water _____________________ 2 Silt and Clay Soils With Considerable Water _______________ 2 River Deposits and Deltas ________________________________ 3 Floating Wetlands—Trembling Earth or Quaking Bog ___________ 3 Wetlands on Mountains __________________________________ 4 Carrs ______________________________________________4 Seepage ___________________________________________4 Spruce Bogs __________________________________________5 Muskeg _______________________________________________ 5 Wetlands With Wildlife That Bite Back _______________________ 5 Environmental and Accessibility Compliance ______7 National Environmental Policy Act and Other Federal Laws ______ 7 The U.S. Army Corps of Engineers _________________________ 7 State and Local Agencies ________________________________ 7 Accessible Trails ________________________________________7 Field Work ________________________________________8 Turned Around _________________________________________8 Trail Layout ____________________________________________8 Reconnaissance _____________________________________8 Preliminary Route—P-Line _____________________________8 Coordination ________________________________________9 Blue Line ___________________________________________9 Final Layout ___________________________________________9 Drawings, Specifi cations, and Cost Estimates ________________ 10 Wetland Trail Structures _________________________14 Sustainable Design ____________________________________14 Corduroy ____________________________________________14 Turnpikes ____________________________________________15 Causeways ___________________________________________17 Improving Drainage ____________________________________17 Dips or Ditches _____________________________________17 Culverts___________________________________________ 18 Structures Requiring Foundations ________________21 Sleepers (Sills) ________________________________________21 Cribbing _____________________________________________22 Wooden Piles _________________________________________22 End-Bearing Piles ___________________________________23 Friction Piles _______________________________________23 Bent Construction______________________________________ 24 Helical Piles (Screw Piles) _______________________________ 26 Helical Pile Assembly ________________________________27 Special Site Considerations ______________________________ 28 Puncheon ____________________________________________29 iii Contents Type 1 Puncheon ___________________________________29 Type 2 Puncheon ___________________________________30 Type 3 Puncheon ___________________________________30 Puncheon Summary _________________________________31 Gadbury _____________________________________________31 Bog Bridge ___________________________________________32 Bog Bridge on Sleepers ______________________________ 33 Bog Bridge on Cribbing ______________________________ 33 Bog Bridge on Piles _________________________________ 33 Bog Bridge Summary ________________________________33 Boardwalk ___________________________________________33 Stringers __________________________________________33 Boardwalk Summary_________________________________ 34 Finishing Details _________________________________35 Decks _______________________________________________35 Posts _______________________________________________35 Pedestrian Railing Types ________________________________36 Railing Installation ___________________________________ 37 Curbs (Bull Rails) ______________________________________ 38 Bulkheads (Backwalls, End Dams, Faceplates) _______________ 39 Floating Trails ___________________________________40 Construction Materials ___________________________41 Choosing Materials ____________________________________41 Logs ________________________________________________41 Lumber and Timber ____________________________________41 Decay-Resistant Wood __________________________________42 Naturally Decay-Resistant Wood _______________________42 Preservative-Treated Wood____________________________ 42 Recycled Plastic _______________________________________43 Hardware ____________________________________________43 Connectors ________________________________________43 Nails _____________________________________________44 Bolts _____________________________________________44 Lag Bolts (Lag Screws) _______________________________ 44 Washers __________________________________________44 Nuts _____________________________________________45 Wood Screws (Deck Screws) __________________________45 Steel Reinforcing Bars _______________________________45 Staples ___________________________________________45 Hardware Cloth _____________________________________45 Geosynthetics ________________________________________46 Nonslip Gratings and Grit-Treated Mats _____________________ 47 iv Contents Roughened Wood Surface ____________________________47 Mineral Paper ______________________________________47 Fishing Net ________________________________________48 Cleats ____________________________________________48 Construction Tools _______________________________49 Measuring Tapes ______________________________________49 Framing Squares ______________________________________49 Plumb Bob ___________________________________________49 Levels _______________________________________________49 String or Line Levels _________________________________ 50 Stringlines _________________________________________50 Chalklines _________________________________________50 Carpenter’s and Mason’s Levels ________________________ 50 Torpedo Levels _____________________________________51 Post Levels ________________________________________51 Surveyor’s Transits and Electronic Instruments _______________ 51 Surveyor’s Levels or Transits___________________________ 51 Electronic Distance Measuring Instruments _______________ 51 Saws _______________________________________________52 Handsaws _________________________________________52 Chain Saws ________________________________________ 52 Hand-Held Pruning Saws _____________________________52 Axes ________________________________________________53 Adzes _______________________________________________53 Planes ______________________________________________53 Draw
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