Non-Linear Time History Analysis of A Highly Horizontally Curved Bridge on Yerba Buena Island (YBI) WB On-Ramps, Bay Bridge, San Francisco, CA

摘要

Seismic issues are international interests. Non-linear Time History Analysis simulates the structure behavior under severe Earthquake movement more properly than other methods. In this paper, Non-linear time history analysis will be presented with one of the world famous project. Yerba Buena Island (YBI) West-Bound (WB) Ramps are portion of San Francisco-Oakland Bay Bridge Project. The Ramps are touched down to Yerba Buena Island (YBI) from YBI WB Widening by hinges. This project is located at a 0.627g Site Specific Response for Safety Evaluation Earthquake (SEE). YBI WB On-ramp is a highly horizontally Curved Bridge with radius of 127.3 feet (38.8 meters). Seismic behavior is very important for the project. In order to understand structural non-linear behavior, especially highly horizontally curved bridge behavior under severe earthquake events, YBI WB On-ramp stand-alone bridge is analyzed by non-linear time history analysis method. SAP 2000 with Hilber-Hughes-Taylor a direct integration method is used for Non-linear Time History Analysis (NL-THA). Seismic Modeling is discussed in this paper. Then six sets of acceleration time histories are used for NL-THA by SAP 2000. Open System for Earthquake Engineering Simulation (Open-SEEs) program developed by University of California-Berkeley is used to verify the SAP NL-THA accuracy in this paper. Site Specific Response Spectra ARS is also used for liner analysis and compared with results of Non-linear Time History Analysis and Open-SEEs Analysis. Non-linear push-over analysis is performed to determine the structural capacity and ductility under severe earthquake events. Finally, discrepancies between different program analyses are discussed and recommendations are presented.