Response Spectrum Analysis of Bridges Subjected to Differential Support Motions Based on Loma Prieta EarthquakeData

这是一个从1989年10月Loma Prieta地震中吸取工程教训的事后调查项目。Loma Prieta地震数据将用于开发一种新的反应谱方法，用于分析桥梁和其他多重支撑受差地震动影响的结构。建立了考虑行波、衰减、传播路径以及当地土壤和地质结构影响的海湾大桥支座运动频率相关模型，并进行了校正。该函数将应用于基于随机过程原理的响应谱分析。新的反应谱方法将用于研究海湾大桥在Loma Prieta地震中的反应，并确定其失效的原因。将特别强调确定不同的支撑运动对观察到的桥梁性能的影响。该分析结果将与伯克利分校的另一个研究小组计划的桥梁时程分析进行比较，从而验证响应谱方法。然后，该方法将用于预测巴桥对圣安德烈亚斯或海沃德断层可能发生的大地震的反应。这一部分将与加州大学伯克利分校对海湾大桥的其他计划研究同时进行。该研究将为分析桥梁在多支承地震作用下的响应提供新的方法。

This is a post-event investigation project to learn engineering lessons from the Loma Prieta earthquake (October 1989) The Loma Prieta earthquake data will be used to develop a new response spectrum method for analysis of bridges and other multyply supported structures that are subjected to differential ground motion. A frequency dependent correlation model for the support motions of the Bay Bridge, accounting for the effects of traveling waves, attenuation, propogation path, and local soil and geologic structures will be constructed and calibrated. This function will be applied to the response spectrum analysis based on the principles of stochastic processes. The new response spectrum method will be used to investigate the response of the Bay Bridge during the Loma Prieta earthquake and to determine the causes of its failure. Special emphasis will be given to determining the influence of differential support motions on the observed performance of the bridge. The results from this anlysis will be compared with planned time-history analysis of the bridge by a separate research team at Berkeley, thus verifying the response spectrum method. The method will then be used to predict the response of the Ba Bridge to a potential earthquake of large magnitude on San Andreas or Hayward faults. This part will be carried out in parallel with other planned studies of the Bay Bridge at the Universit of California at Berkeley. The investigation will advance the methodology for analyzing the bridge response to multiple-support seismic excitations.