Breakwaters and Partially Penetrating Wave Barriers Brochure

Home , Breakwater (structure)

PND Engineers, Inc. is a full-service consulting engineering firm that provides civil, marine, geotechnical, structural, surveying and construction inspection services for a wide range of projects. The firm was founded in 1979, with offices now located in Anchorage and Juneau, Alaska, and in Seattle, Washington.

PND has performed planning, design, and construction inspection for a significant number of marine facilities. These projects have included the design of floating and fixed docks, passenger boarding gangways, fender systems, and upland facilities that are used by various sized PPOOROOR SOILSSOILS,, HHARSHA RSH MARIMA R I vessels including cruise ships, ferry vessels, and recreational facilities for pleasure craft. PND has the advantage of knowing the detailed requirements related to all phases of the design, construction, ENVIRONMENT, DYNAMIDYNAMICC operation and maintenance for these types of projects. WAWAVEVE LOADS,LOA DS, POOR SOILSSOILS SSEDIMENTATION,EDIMENTATION,BREAKWATERS SCOUR, CCORROSION,ORROSION,INCLUDING PARTIAL VVARIABLE PENETRATINGA RIA BLE TTIDES,IDES,WAVE ICE, BARRIERS EEARTHQUAKEA RTHQ UA K E SSHORELINEHORELINE EROEROSION,S ION, PO OOILS,ILS, HHARSHA RSH MARINEMA RINE ENVIRONMENT, DYNAMIDYNAMICC WAWAVEVE LOADS,LOA DS, POOR SOILSSOILS SSEDIMENTATION,EDIMENTATION, SCOUR, CCORROSION,ORROSION, VVARIABLEA RIA BLE TTIDES,IDES, ICE, EARTHEARTHQUAKEQ UAKE P N D Headquarters: Anchorage Office Juneau Office Seattle Office SSHORELINEHORELINE EROEROSION,S ION, PO E NGINEERS, I NC. 1506 West 36th Avenue 9360 Glacier Highway, Suite 100 811 First Avenue, Suite 570 Anchorage, Alaska 99503 Juneau, Alaska 99801 Seattle, Washington 98104 Phone: 907.561.1011 Phone: 907.586.2093 Phone: 206.624.1387 OOILS,ILS, HHARSHA RSH MARINEMA RINE Fax: 907.563.4220 Fax: 907.586.2099 Fax: 206.624.1388 P N D

A breakwater is a structure protecting a harbor, anchorage or shoreline from waves. There are PND has specialists in oceanography, coastal engineering essentially three types: rubble-mound, vertical and marine construction. Specialists wall, and floating. have direct project experience that includes all five shorelines of North PND’s coastal engineers are experienced in America (Arctic, Pacific, Gulf of designing all types of breakwaters and jetties, Mexico, Atlantic and Great Lakes) in through all the phases of projects, from concept addition to projects overseas. DESIGN CHALLENGES design through construction. PND has designed breakwaters in a large range of site conditions: Breakwater design is a challenging field in which designers must rely upon sound judgment and experience to • Dynamic Wave Loads efficiently solve problems associated with uncertainties in • Poor Soils various environmental conditions. Relative to other • Scour engineering professions, design standards and codes often • Corrosion do not address the wide array of potential design conditions. Design demands the expertise and experience • Sensitive Ecosystems with Stringent Permitting Requirements of those who specialize in coastal engineering. • Extremely Variable Tides PND is well-qualified to analyze wind, wave, tide and • Ice currents to determine wall heights, depths, and allowable • Earthquakes wave transmission for any number of site conditions, • Shoreline Erosion/Accretion including hindcast studies and wave reflection/refraction analysis. PND also has experience in specialized areas that can significantly affect project performance including boat wakes, scour, propwash and corrosion protection. Structure Types for Typical Range of Wave Height & Period

BREAKWATER TYPES 30

The choice of a breakwater type is largely dependent on 25 wave height and period. The largest waves require rubble- 20 Rubble-Mound and Filled Structures mound structures that are able to absorb wave energy. 15 Full-Height Vertical Floating breakwaters can be used for smaller wave heights Structural Wall and periods, and allow for transient moorage space. 10 Partial Penetrating

Vertical structural wall types address the range falling Height (feet) Wave Vertical Wall 5 between that of rubble-mound and floating breakwaters, Floating as shown in the diagram on the right. 5 10 15 20 25 30 Wave Period (seconds)

PND | BREAKWATERS B REAKWATERS

BREAKWATER TYPES 30

PND | BREAKWATERS TRADITIONAL BREAKWATER STRUCTURES

ST. GEORGE RUBBLE-MOUND BREAKWATER PORT ORCHARD WEST BREAKWATER In the Pribilof Islands in Alaska, this rubble-mound, berm-type breakwater was originally designed by PND in the early 1980’s. It provides moorage and safe PND provided design for a floating breakwater at the Port refuge for a fishing fleet. Physical conditions at St. George are extremely harsh, Orchard Marina on Washington’s Puget Sound that protects the with heavy icing and waves that reach up to 42 feet high. marina and serves as transient moorage. The marina has waves of up to four feet in height. After 22 years of extreme storms, a massive storm hit that caused non-critical breakwater damage. Due to the exceptional past performance, PND was asked to provide design repairs. Eight thousand cubic yards of quarry rock ranging from LA CONNER G-FLOAT 50-2,500 pounds were required on the north shoreline, topped with 8,000 tons of Port Orchard West Breakwater is located armor rock. The south breakwater arm required 18,000 tons of armor rock. on the west side of the marina (to the G-Float is a floating breakwater that provides protection for the right of the above photograph). La Conner Marina North Basin in Washington. The breakwater is an 800-foot x 9-foot modular concrete float on the marina’s outer CASCADE POINT MARINE FACILITY BREAKWATER perimeter and also provides transient moorage. Cascade Point is the site of a rubble-mound breakwater that will protect floats and a dock for a gold mine near Juneau, Alaska. The site is constrained by relatively steep underwater slopes and the breakwater is designed to accommodate future expansion. The typical armor rock size is nominally four feet in diameter. A cross-section of the breakwater is shown below.

The La Conner breakwater is located on the west side of the marina (in the front of the photograph).

PND | BREAKWATERS TRADITIONAL BREAKWATER STRUCTURES

The La Conner breakwater is located on the west side of the marina (in the front of the photograph).

PND | BREAKWATERS PARTIAL PENETRATING BLAINE HARBOR WAVE BARRIER HARBOR PROTECTION & PROMENADE

The need to protect facilities from moderate-height waves has New partial penetrating wave barriers were installed at led PND to develop the partial penetrating wave barrier, a vertical the primary harbor entrance for the Port of Bellingham barrier stopping short of the seafloor. In most situations, a at Blaine Harbor in Washington. The wave barriers partial penetrating wave barrier is the best breakwater choice, replaced deteriorating timber pile barriers protecting providing effective protection while minimizing the footprint the harbor's entrance. The timber pier was rehabilitated of the structure. and turned into a park. The new 580-foot wave barriers vary from 20 to 50 feet in height from mudline, and RESEARCH & DEVELOPMENT were designed to improve wave protection, decrease maintenance costs, and provide additional space for moorage just inside the entrance to the harbor. PND has been leading research including physical/numerical modeling on the partial penetrating wave barrier since it was The wave barriers used two different design styles first designed at a Coast Guard facility in Oregon in 1980 chosen to best fit varying site conditions. In shallower (pictured at top left). Extensive model testing helped to water, a cantilever-type wave barrier was employed, establish design methods and criteria published in 2001 that which consists of large-diameter pipe piles with partial addressed incident and transmitted wave heights, wave period depth sheetpile barrier wings. The deeper water areas and length, run-up, and forces for various structural necessitated use of Spin Fin™ batter clusters to handle configurations. From these criteria, suitable structural solutions the repetitive tension / compression loads from wave and use limitations can be developed for different soil attack. The design surface waves have a significant conditions, water depths, and other factors. Model testing has CLEAR height of 6.2 feet, with period of 4.6 seconds. ZONE been performed in wave tanks at B.C. Research, Inc., the U.S. Naval Academy, Oregon State University, and PND. The photo on the right depicts the wave barrier in February of 2006, during the largest storm in SYSTEM ADVANTAGES conjunction with the highest storm surge in 40 years.

- Reduces construction and maintenance costs SECTION & FOOTPRINT - Reduces construction time Rubble-Mound Breakwater and - Minimal space required Partially Penetrating Wave Barrier - Allows natural basin flushing - Minimizes impact on the marine environment - Minimizes loading on submarine soils - Reduces the breakwater's susceptibility to seismic damage - Does not require rock quarrying and related activities - May be attached directly to existing docks - May be used as a part of foundation system for future docks The size of the wave barrier increases as the water depth increases. - Can be removed readily for modification or expansion - Allows construction in deep water

PND | BREAKWATERS PARTIAL PENETRATING BLAINE HARBOR WAVE BARRIER HARBOR PROTECTION & PROMENADE

PND | BREAKWATERS SHILSHOLE PIER A WORK DOCK COMBINATION

A realigned partial penetrating wave barrier structure with a concrete work dock was constructed at Shilshole Marina's Pier A for the Port of Seattle in Washington. The new dock allows vehicle access for loading of large vessels.

Partial depth steel sheet pile barrier wings, welded onto the pipe pile, were driven and attached to a steel beam to handle wave loads. Spin Fin™ batter clusters were used to convert the wave forces into tension and compression to transfer forces into the soil. The batter pile clusters were also used to support the precast concrete promenade. Floats on the back side of the dock were included for 100-foot vessels.

The placement of the wave barrier on the inside face of the pier and the openings for The top photo shows the West Basin fish passage have improved the flushing of prior to breakwater construction. The water through the marina. large photograph depicts the 22 additional moorage locations.

WEST BASIN WAVE BARRIER HARBOR PROTECTION & EXPANSION

A partial penetrating wave barrier in Astoria, Oregon provided expansion room for 22 additional 60-foot vessel slips by eliminating a filled bulkhead system. The alignment of the new breakwater allowed for the additional moorage.

The West Basin marina is located near the mouth of the Columbia River in Oregon where there are strong currents, high winds and ocean-going cargo CLEAR ZONE vessels. The largest design loads are developed by 4.9-foot high significant waves with 4.3-second periods. A cantilever-style wall was selected that consists of large-diameter pipe piles with sheetpile barrier wings. This design provided the best wall alignment to protect the harbor without impeding access and creating wave-reflection issues. A typical section is shown to the right.

PND | BREAKWATERS SHILSHOLE PIER A WORK DOCK COMBINATION

WEST BASIN WAVE BARRIER HARBOR PROTECTION & EXPANSION

PND | BREAKWATERS CAPE DISAPPOINTMENT BOAT LAUNCH PROTECTION

PND provided services to the Washington State Parks Department for a partial penetrating wave barrier at Cape Disappointment State Park in Southern Washington State. The barrier protects a three-lane recreational boat launch facility, and was designed to replace an old timber barrier. The new cantilever wave barrier is approximately 250 feet in length and consists of galvanized pipe piles with sheet pile wings.

The partial penetrating design was selected because BELL STREET PIER of its low environmental impact and small footprint. The barrier design also has a separation that allows CRUISE SHIP FACILITY for fish passage. Bell Street Pier is a waterfront facility in downtown Seattle, Washington that provides public moorage, cruise ship operations, a maritime museum, a conference facility, and waterfront restaurants. The harbor is protected with a 900-foot partial penetrating wave barrier with lateral resistant battered Spin Fin™ piles.

The wave barrier was designed to resist storms producing 8-foot significant height waves with six-second periods. The wave barrier face extends into the water 32 feet at low tide. It is comprised of 48-inch diameter pipe piles placed 12 feet on-center acting as the vertical bending members. Bridging the gap between these piles are eight-inch-thick prestressed concrete panels. The height of the structure from mudline varies between 55 and 75 feet.

A three-dimensional wave model of the surrounding Elliot Bay (bottom right) was used to verify wave climate and barrier efficiency at B.C. Research Lab in Vancouver, Canada.

PND | BREAKWATERS CAPE DISAPPOINTMENT BOAT LAUNCH PROTECTION

A three-dimensional wave model of the surrounding Elliot Bay (bottom right) was used to verify wave climate and barrier efficiency at B.C. Research Lab in Vancouver, Canada.

PND | BREAKWATERS PND Engineers, Inc. is a full-service consulting engineering firm that provides civil, marine, geotechnical, structural, surveying and construction inspection services for a wide range of projects. The firm was founded in 1979, with offices now located in Anchorage and Juneau, Alaska, and in Seattle, Washington.

PND has performed planning, design, and construction inspection for a significant number of marine facilities. These projects have included PPOOROOR SOILS, HARSH MARMARII the design of floating and fixed docks, passenger boarding gangways, fender systems, and upland facilities that are used by various sized vessels including cruise ships, ferry vessels, and recreational facilities ENVIRONMENT, DYNAMIDYNAMICC for pleasure craft. PND has the advantage of knowing the detailed requirements related to all phases of the design, construction, WAVE LOADS, POOR SOILSOILSS operation and maintenance for these types of projects. SSEDIMENTATION,EDIMENTATION,BREAKWATERS SCOUR, CORROSION,INCLUDING PARTIAL VARIABLE PENETRATING TIDES,WAVE ICE, BARRIERS EARTHQUAKEARTHQUAKE E P N D Headquarters: Anchorage Office Juneau Office SSHORELINEHORELINE EROSION, PO E NGINEERS, I NC. 1506 West 36th Avenue 9360 Glacier Highway, Suite 100 Anchorage, Alaska 99503 Juneau, Alaska 99801 OOILS,ILS, HARSH MARINE Phone: 907.561.1011 Phone: 907.586.2093 Fax: 907.563.4220 Fax: 907.586.2099 ENVIRONMENT, DYNAMIDYNAMICC Seattle Office Houston Office 1736 Fourth Avenue S, Suite A 10497 Town and Country Way, Suite 210 WAVE LOADS, POOR SOILSOILSS Seattle, Washington 98134 Houston, Texas 77024 Phone: 206.624.1387 Phone 832.930.4830 Fax: 206.624.1388 SSEDIMENTATION,EDIMENTATION, SCOUR,

PND Engineers Canada, Inc. CORROSION, VARIABLE Vancouver Office Suite 2000, Oceanic Plaza 1066 West Hastings Street TIDES, ICE, EARTHQUAKEARTHQUAKEE Vancouver, BC V6E 3X2 Phone: 604.601.5247 SSHORELINEHORELINE EROSION, PO OOILS,ILS, HARSH MARINE For additional information please visit our website. www.pndengineers.com P N D