Performance of Suspension Bridges During Strong Earthquake

在这个项目中，将研究1987年惠蒂尔地震期间位于文森特托马斯桥及其附近的26个加速度计所采集的强震记录。这项研究将：(i)定义具有代表性和适当相关的非同步支撑运动，（ii）验证现有的分析建模和地震分析，（iii）开发处理多输入多输出模型（线性和非线性）的系统识别技术，（iv）评估地震期间桥梁的性能，(v)优化仪器投资回报，提高记录响应数据的有用性，（vi）提出加强或改造现有索桥的总体方案，（vii）获得关于阻尼值作为振动幅度的函数的信息，（viii）获取该大型结构的土-结构相互作用信息；（ix）开发弹性止水带或其他特殊装置，以减弱地震和风力的影响。该研究将满足对这些独特的历史反应记录进行全面调查的迫切需要，以确保在全国地震带广泛使用的悬索桥的安全。研究结果将对现有索桥的加固（以及设计新的结构，升级和安装新的监测仪器）具有极其重要的意义。

In this project the strong motion records taken from the 26 accelerographs located on and in the vicinity of the Vincent Thomas Bridge during the 1987 Whittier Earthquake will be studied. The study will: (i) define representative and appropriately correlated non-synchronous support motions, (ii) validate existing analytical modelling and seismic analysis, (iii) develop system identification techniques that deal with multiple-input multiple-output models (both linear and nonlinear), (iv) evaluate the bridge performance during the earthquake, (v) optimize the return on the instrumentation investment and improve the usefulness of the recorded-response data, (vi) propose a general program for strengthening or retrofitting of existing cable-supported bridges, (vii) obtain information on damping values as a function of the vibrational amplitudes, (viii) obtain information on the soil-structure interaction of this massive structure, (ix) develop elastic stoppers or other special devices to dampen the effects of seismic and wind forces. The study will fulfill an urgent need for comprehensive investigations of these unique and historical response records to insure the safety of suspension bridges which have been widely in use across the nation's seismic zones. The research results will be of extreme importance to strengthen existing cable-supported bridges (as well as to design new structure, and for up-grading and installing new monitoring instrumentation).