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

这是一个事后调查项目，目的是从洛马普列塔地震(1989年10月)中吸取工程经验教训。Loma Prieta地震数据将被用来开发一种新的反应谱方法，用于分析桥梁和其他承受差异地面运动的多支承结构。考虑行波、衰减、传播路径以及局部土体和地质结构的影响，建立和标定了海湾大桥支座运动的频变相关模型。将该函数应用于基于随机过程原理的反应谱分析。新的反应谱方法将用于研究海湾大桥在洛马普里塔地震期间的反应，并确定其失效原因。将特别强调确定不同支承运动对桥梁观测性能的影响。本次分析的结果将与伯克利的另一个研究小组对大桥进行的计划时程分析进行比较，从而验证反应谱方法。然后，该方法将被用于预测巴大桥对圣安德烈亚斯或海沃德断层上潜在的大地震的反应。这一部分将与加州大学伯克利分校其他计划中的海湾大桥研究同步进行。该研究将为桥梁在多点地震激励下的响应分析提供新的方法。

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.