EARTHQUAKE ENGINEERING

West Oakland BART Station
Location: Oakland, California

This station is part of the "core" system and has a higher, continuous operations performance standard that exceeds Caltrans and California Building Code life safety - collapse prevention, earthquake performance standards. Structural earthquake response is limited to prevent damage so the BART system can continue passenger service immediately after a post-earthquake safety inspection.

Creegan + D’Angelo Engineers served as the prime consultant for a team providing final engineering and design of the seismic upgrade for this station. C+D provided project management to coordinate the work of the architect, landscape architect, electrical, mechanical, traffic engineers, cost estimators, and geotechnical subconsultants. C+D furnished the structural engineering, earthquake engineering, and civil engineering services on this $1.3 million fee, $11 million construction project. It is the first East Bay BART station and all westbound trains travel through the West Oakland Station.

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Wawona Covered Bridge
Location: Yosemite National Park, California

C+D Consulting Engineers is Yosemite National Park's selected "on-call" structural engineer since 2000. This project is the rehabilitation of the historic 1858 Wawona Covered Bridge over the South Fork of the Merced River. C+D provided structural engineering and material testing for the rehabilitation construction and National Historic Landmark registration of this historic hand-built bridge. Work includes using historically replicated large timbers to replace rotted floor framing and strengthen bridge for wind and seismic loads.

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San Francisco International Airport Terminal, Upper Level Viaduct
Location: San Francisco, California

The elevated loop viaduct at San Francisco International Airport serves the departure level of the terminals at this major airport. The viaduct is a unique structural system that uses precast wing girders placed on a post-tensioned spine beam. Located on soft bay mud near the San Andreas Fault, it will be subject to strong seismic shaking in the event of a major earthquake. To identify deficiencies in the structure, C+D performed a detailed dynamic analysis, which included site-specific response spectra and soil-structure interaction effects.

We developed retrofit schemes for the deficient pile foundations and columns. Construction of the retrofits will be complicated by the need to maintain continuous access to the terminals, and because some of the viaduct is contained within the terminal buildings.

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Interstate 5 and Highway 4 Interchange
Location: Stockton, California

C+D has conducted seismic evaluations and prepared construction plans for bridges throughout California. The goal is to prevent collapse in the event of a major earthquake.

For this interchange, we provided evaluations, seismic assessment and construction plans, and specifications.

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Tracy Boulevard Bridge
Location: San Joaquin County, California

Tracy Boulevard Bridge at Grant Line Canal is a pile supported steel double leaf bascule bridge with reinforced concrete flat slab approach spans. Retrofits included main trunnion bearing brackets, seat extenders, hinge restrainers, and reinforced concrete bentcaps with PC/PS concrete driven piling. C+D worked with the County to attain NEPA, CEQA, NOAA and Reclamation Board clearances.

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Airport Way Bridge
Location: San Joaquin County, California

Airport Way Bridge across San Joaquin River is a 546 ft long, 5 span, CIP/RC Box Girder Bridge supported on tapered reinforced concrete piers and seat type abutments. Abutments and piers are supported on concrete filled steel pipe piles and original construction was completed in 1965. Retrofits include timber bumpers, catcher blocks, hinge cable restrainers, pipe seat extenders, and reinforced bentcap extensions with 5’ diameter CISS piles. C+D worked with the County to attain NEPA and CEQA clearance, and incorporated requirements from numerous agencies including NOAA, State Reclamation Board, and US Coast Guard, into the construction documents. During construction, a large bat colony was found within the hinges and C+D designed a Bat Roost mounted on the bentcap retrofits.

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