
Grand Island Bridges Seismic Evaluation
Challenges Solved
The Grand Island Bridges are two pairs of twin two-lane truss arch bridges in New York, United States. The South Grand Island Bridge twins cross the Niagara River between Tonawanda and Grand Island, and the North Grand Island Bridge twins cross the Niagara River between Grand Island and Niagara Falls. MRCE performed a site‐specific seismic study to evaluate the seismic hazard at all four Grand Island Bridges. The seismic hazard evaluation incorporated updates in current knowledge of the seismicity and seismic sources of the area, recently developed ground motion attenuation equations and ground motion models, and effects of the locally varying site conditions. The site-specific seismic study included a Probabilistic Seismic Hazard Analysis (PSHA), acceleration time history generation, seismic Crosshole testing, site response analysis, and liquefaction potential analysis.