Constructed in 1954, the Major Deegan Expressway Bridge has 6 lanes of traffic and consists of two approximately 120 ft. long spans framed with steel plate girders and supported on concrete abutments and center pier. The project is to replace the bridge superstructure and reuse the existing abutments and pier. The new deck will be widened by approximately 5 ft. on each side to improve some of the substandard roadway features. This will increase the loads on the existing abutments, piers and foundations and some retrofit will be required. At the approaches, the widened roadway will be cantilevered out from the existing wing walls in order to minimize the impact on the adjacent property.
YU & Associates provided geotechnical engineering services including: 1) review of relevant available drawings and subsurface data, 2) subsurface conditions evaluation, 3) determination of lateral earth pressures, seismic design parameters, load bearing capacities of the existing bridge abutment and pier foundations, which involved both piles driven to glacial till or rock and footings on rock, 4) design recommendations for foundation and wing/abutment wall retrofit.