Eureka Hill Road over The Garcia River Seismic Retrofit Project

Eureka Hill Road over The Garcia River Seismic Retrofit Project

The proposed project includes seismic retrofits of the Eureka Hill Road Bridge (No. 10C-0034) over the Garcia River in Mendocino County. The proposed improvements would strengthen the structural components to resist seismic loads on the structure & loads imposed by the soil movement. Support is provided at the ends of the superstructure near the abutments. The retrofit work would involve the following activities within or adjacent to the Garcia River: 1) constructing a temporary clear water crossing (temporary work pad) beneath the bridge with temporary culverts to maintain flow & fish passage through the site as well as providing construction access to piers; 2) excavating, driving piles, and constructing top mats to reinforce the bent foundations around piers 2, 3, and 4; and 3) revegetating temporarily disturbed riparian areas. Retrofitting of the bridge abutments (i.e., excavating, constructing two 72-inch Cast-In-Drilled-Hole (CIDH) piles at each bridge abutments, and constructing concrete girders between the CIDH pile groups and bumpers to the superstructure soffit would occur outside of the channel. In order to complete the needed seismic retrofit work, it is likely that the Eureka Hill Road Bridge would be limited to one lane traffic control through the project site for some construction activities, including drilling CIDH piles. Limited east-west connections exist between State Routes 1 and 128, and closing Eureka Hill Road and detouring traffic would result in a 125-mile detour around the project site. Two areas (one on each side of the Garcia River) north of the bridge are available for potential construction staging areas. All in-channel work would occur between June 15 and October 15.

Point Arena

Mendocino