Stevenson Bridge (23C0092) at Putah Creek Rehabilitation Project

Stevenson Bridge (23C0092) at Putah Creek Rehabilitation Project

Bridge Rehabilitation - Seismic assessment of the bridge showed that many of the existing structural components of the bridge are unable to withstand seismic loads without retrofitting. Flexural and shear !demands exceeded the corresponding capacities, requiring retrofit or replacement of several structural members in order to meet safety requirements. Deficient components include the bridge railing, deck spalling and carbonation deck drains, cracking of approach spans, and substandard south approach alignment. In addition, the hydraulic analysis determined the structure is scour critical and scour mitigation will be required to maintain the structural integrity of the bridge. Bridge rehabilitation work will be conducted on the deck, piers, abutments, bent caps, hanger column, retaining wall, concrete railings, and approach spans. Deck drains will be removed, reconstructed, and refinished. The concrete railing will also be refinished, and the spalled and delaminated concrete will be patched. A hanger column will be removed and reconstructed, and the arch ribs from the spring line to the first column will be fiber wrapped. Piers 1, 2, and 3 will also be fiber wrapped. The pier curtain wall will be removed and reconstructed at Piers 1 and 2. Two cast-in-drilled-holes (CIDH) piling and pier footing overlays will be constructed at Piers 1, 2, and 3, and two CIDH piling and caps will be placed behind the abutments. Exterior girders and bent caps will be bolstered. The retaining wall on the south side of the bridge will be reconstructed, and 1 O feet of the approach span slab will be removed and reconstructed. Rock slope protection will be used to stabilize the creek bank around the abutments and prevent scour. Pier bents will have 5 to 7 feet of excavation immediately around them for installation of scour protection measures. Road Approach Realignment - Stevenson Bridge Road will be realigned to eliminate two sharp turns just south and east of the bridge, one of which is a 90-degree curve. The roughly 1,000-foot realignment will go through an existing orchard and transition onto the existing road alignment near Strathgordon Lane. The realigned road will comply with County standards and provide for safer vehicle passage. Realignment of the south approach will require right of way (ROW) acquisition from one privately owned parcel, APN 0107-020-040. Fill will be needed to create the new roadway alignment. No buildings or other structures on the privately owned parcel will need to be relocated or removed as a result of the proposed realignment. Staging Area - The area above the northeast creek bank between County Road 95A and the access road will be used as a staging area. General bridge construction equipment to be used includes, but is not limited to, haul trucks, backhoes, dump trucks, excavators, grade-alls, bulldozers, drilling, equipment, water trucks, concrete delivery trucks, and service vehicles. Access Road and Temporary Creek Crossing - An access road will be cut in east of the bridge, on the north bank of Putah Creek, to access Piers 1 and 2. A temporary access road splits off from the permanent road at the top of the slope to access Pier 3. The access road will be composed of gravel and allow construction equipment to access the creek bed and the underside of the bridge. A creek crossing will be constructed between Piers 1 and 2, using either culverts and fill or a temporary low-span bridge. Traffic Detour - Road closure will be required during road construction and bridge rehabilitation work. Traffic will be detoured using a loop along Stevenson Bridge Road, Sievers Road, Pedrick Road, Russell Boulevard, and Road 95A, with a maximum length of 13.7 miles. Utility Relocation - Overhead poles with electric and phone lines occur along the south bridge approach, cross Putah Creek parallel to each side of the bridge, and continue north of the bridge. It is uncertain whether the poles and lines will need to be relocated. If relocation is necessary, the utility companies will be required to move the utilities prior to construction:

Unincorporated Winters

Solano

Unincorporated

Solano