ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/657823
During the construction of California's h i g h w a y s y s t e m , h u n d r e d s o f c u l v e r t s w e re i n s t a l l e d t o a l l o w creeks to flow under roads. Many of these culverts acted as barriers to migrating fish, effectively cutting off upstream access. The Fort Goff Creek Bridge was proposed in response to the commitment by the California Department of Transportation (Caltrans) to restore fish passage in California. Califor nia Senate Bill 857 (Kehoe, Chapter 589, Statutes of 2006) and Article 3.5 of Chapter 1 of Division 2 of the California Streets and Highways Code require the removal of barriers to fish passage where highways cross anadromous fish-bearing streams. Anadromous fish are migratory fish that breed in fresh water and spend a portion of their lives in the ocean. The barrier caused by the culvert carrying the water of Fort Goff Creek under State Route 96 was identified by Caltrans as a top-priority fish- passage remediation project. The streambed restoration project replaced the 15-ft-diameter corrugated metal pipe culvert with the Fort Goff Creek Bridge, a 60-ft-long, single-span precast concrete structure. Construction of the bridge allowed for the channel section and the stream bed beneath the highway to be restored to a natural state, providing unimpaired passage for anadromous fish. Removal of the barrier opened miles of habitat for the migration, spawning, and rearing of threatened and endangered species including steelhead trout and Chinook and Coho salmon. Structure Selection The project, in a remote part of Northern California along the Klamath River in Siskiyou County, presented a number of challenges to conventional cast-in-place concrete construction. The site is located in a severe climate area where freezing and thawing cycles and heavy salting occur frequently, and tire chain use is common. These conditions require special attention to the longevity of the bridge deck and the structure in general. The nearest ready-mixed concrete batch plant is located approximately 90 minutes away, which created a situation where cast-in-place concrete quality could be compromised by traffic delays. Traffic profile FORT GOFF CREEK BRIDGE / SISKIYOU COUNTY, CALIFORNIA BRIDGE DESIGN ENGINEER: California Department of Transportation, Sacramento, Calif. PRIME CONTRACTOR: Stewart Engineering, Redding, Calif. PRECASTER: KIE-CON Inc., Antioch, Calif.—a PCI-certified producer POST-TENSIONING CONTRACTOR: Schwager Davis Inc., San Jose, Calif. The existing culvert blocked fish passage due to the slope of the culvert and the vertical drop at the inlet and outlet. Fort Goff Creek Bridge. All Photos: Caltrans. 18 | ASPIRE Spring 2016 P R O J E C T Fort Goff Creek Bridge A project to restore fish passage by Dorie E. Mellon, California Department of Transportation