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From page 1... ... Research Results Digest 330 Subject Areas: IB Energy and Environment; IIC Bridges, Other Structures, Hydraulics and Hydrology; IIIB Materials and Construction Responsible Senior Program Officer: Christopher Hedges September 2008 TEMPORARY BRIDGING TO AVOID OR MINIMIZE IMPACTS TO WATERS AND WETLANDS DURING HIGHWAY CONSTRUCTION This digest presents the results of NCHRP Project 25-30, "Temporary Bridging to Avoid or Minimize Impacts to Waters and Wetlands During Highway Construction." Temporary bridging includes prefabricated, portable, and reusable bridging as well as built-in-place structures. The digest is based on successful practices used by U.S. Read the entire page →
From page 2... ... based survey distributed to 107 potential respondents, including AASHTO-affiliated DOT representatives from each of the 50 states, the District of Columbia, and Puerto Rico; U.S. DOT members and associate members from bridge, port, and toll organizations; the U.S. Read the entire page →
From page 3... ... Mitigation and restoration plans also typically included short- to long-term management and recordkeeping and follow-up to correct deficiencies, if they arise. Although factors such as wildlife presence are also used, determining the success of mitigation and restoration is generally based on the threeparameter approach for the existence of wetlands (i.e., hydrology, vegetation, and soils) Read the entire page →
From page 4... ... has authority under some circumstances to veto permits issued by USACE. State agencies also play an important role. Read the entire page →
From page 5... ... neering and environmental measures. Permits needed under the Section 404 program cannot be granted without such attention to impact mitigation. Read the entire page →
From page 6... ... resources can contribute to the overall avoidance and minimization objectives. Temporary bridges and work platforms preclude the use of earthen fills and keep construction equipment away from wetlands and other sensitive aquatic sites. Read the entire page →
From page 7... ... Bailey bridge can support tanks over a 60-m (200-ft) span installation. Read the entire page →
From page 8... ... but also the materials the equipment will be handling must be taken into consideration. Girders and bents. Read the entire page →
From page 9... ... of the new bridge that spans the open water. See Figure 3. Read the entire page →
From page 10... ... the original grade, and to replace native vegetation. Additional compensation may be required for the wetland functions temporarily lost during the period the causeway was in place. Read the entire page →
From page 11... ... • Driven steel piling (H-piles, pipe, prestressed concrete, timber, or sheet piles) with steel or concrete pile caps; • Cast-in-drilled structural concrete columns with a structural concrete abutment cap/seat; or • Structural concrete spread footing/stemwall combination with an integral concrete abutment seat. Read the entire page →
From page 12... ... the resulting subsidence may need to be corrected by re-grading. Benefits of Use For a short-time need, this method is very expeditious and most likely the least costly. Read the entire page →
From page 13... ... failure of the temporary structure. Where the temporary structure is carrying public traffic, the failure of the structure due to flooding or other causes will have an adverse effect on the traveling public. Read the entire page →
From page 14... ... Owner's Permit Provides for Temporary Structure -- Type Not Determined Where the owner has provided the permit, the contractor must take the permit conditions into consideration in the design and construction. Should the contractor not be able to meet the permit conditions with the temporary bridging design, then the contractor, through the owner, will need to apply for and receive a permit modification. Read the entire page →
From page 15... ... tion; (2) subsurface soil; (3) Read the entire page →
From page 16... ... tently flooded wetlands include arroyos, dry washes, and ephemeral streams. Other Considerations Navigable Water In this document, navigable waters are defined as those open water areas that are subject to marine traffic. Read the entire page →
From page 17... ... protect aquatic species during reproductive cycles or spawning seasons and other critical migration periods, state and federal wildlife agencies often enact moratoria that will limit or restrict work in surface waters. Examples of moratoria include the North Carolina Wildlife Resources Commission moratorium that restricts in-water work between January 1 and April 15 to protect rainbow trout spawning, or the U.S. Read the entire page →
From page 18... ... rary structure. Such materials may include steel girders, piles, and timbers. Read the entire page →
From page 19... ... Table 4 Decision matrix for determining the use of temporary bridging applications* Duration Subsurface Soil Wetland Hydrology Other Considerations E q u a l t o o r L e s s t h a n 1 Y e a r G r e a t e r t h a n 1 Y e a r S t a b l e C o n d i t i o n U n s t a b l e C o n d i t i o n T i d a l l y I n fl u e n c e d P e r m a n e n t / S e m i – P e r m a n e n t / S a t u r a t e d S e a s o n a l / T e m p o r a r y I n t e r m i t t e n t l y F l o o d e d N a v i g a b l e W a t e r C o m b i n a t i o n -- N a v i g a b l e W a t e r / W e t l a n d P o t e n t i a l f o r F l o o d i n g E n v i r o n m e n t a l S e n s i t i v i t y R e l a t i v e C o s t F a c t o r ( s e e T a b l e 3 ) Read the entire page →
From page 20... ... State agencies like the Florida DOT and Kansas DOT maintain inventories of temporary bridge components that are easily transportable and can be reused as needs occur. For instance, when Hurricane Katrina destroyed bridges in Louisiana and Mississippi, Florida DOT made its temporary bridge panels available so that roadways could be reopened for emergency response access and to reconnect communities affected by the storm. Read the entire page →
From page 21... ... draw bridge at the site to maintain marine traffic along the Intracoastal Waterway during construction. A specialized crane barge was brought from Louisiana to lift the nearly 400-ton (406.4-metric-ton) Read the entire page →
From page 22... ... may be of any material of sufficient strength and durability to accommodate anticipated loads, traffic levels, and the duration of the temporary bridge. The guideline also includes direction on construction sequencing and support specifications -- for example, erosion and sediment transport control measures should be in place and stabilized prior to construction of the temporary crossing. Read the entire page →
From page 23... ... na/wit/pdf/WIT-05-0029.pdf (as of November 13, 2007) Read the entire page →
From page 24... ... 24 Goodwin, Ken. Read the entire page →
From page 25... ... Transportation Research Board 500 Fifth Street, NW Washington, DC 20001 These digests are issued in order to increase awareness of research results emanating from projects in the Cooperative Research Programs (CRP) Read the entire page →

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... Research Results Digest 330 Subject Areas: IB Energy and Environment; IIC Bridges, Other Structures, Hydraulics and Hydrology; IIIB Materials and Construction Responsible Senior Program Officer: Christopher Hedges September 2008 TEMPORARY BRIDGING TO AVOID OR MINIMIZE IMPACTS TO WATERS AND WETLANDS DURING HIGHWAY CONSTRUCTION This digest presents the results of NCHRP Project 25-30, "Temporary Bridging to Avoid or Minimize Impacts to Waters and Wetlands During Highway Construction." Temporary bridging includes prefabricated, portable, and reusable bridging as well as built-in-place structures. The digest is based on successful practices used by U.S.