Determining the Damageability of the Loma Prieta Earthquake Motions: Predicted and Observed Damageability and Soil Effects

本项目旨在总结1989年10月17日北加州（洛马普里塔）地震的经验教训。目的是评估具有工程意义的洛马·普里塔地震地面运动（包括震后）的关键参数，并证明这些参数在预测未来湾区地震的可损失性方面的使用。关于频率内容的持续时间、时变和宽度、循环历史等的信息——已知对结构损伤有重要影响的运动特性；但是它们很难明确地定义和使用-这些信息隐含地包含在表征中。对洛马·普里塔地震的有效损伤运动特征进行了预报和观测比较。观察到的分析特征用于解释建筑物损伤和非损伤的具体情况，而土壤对运动特征的影响是统计确定的。这些来自洛马普列塔地震的数据与早期地震事件的计算数据相结合。该项目预计将改进非线性损失性的幅度/距离/土壤依赖的统计公式。这些公式与当地土壤数据相结合，用于进行概率危害分析，以得出未来湾区地震的可损害性图。

This project addresses the lessons learned from the 17 October 1989 Northern California (Loma Prieta) earthquake. The aim is to evaluate critical parameters of the Loma Prieta earthquake ground motions (including after shocks) that have engineering significance, and to demonstrate the use of these parameters in predicting the damageability of future Bay Area earthquakes. Information on the duration, time-variation and breadth of frequency content, cyclic history, etc. - motion properties known to have important effects on structural damage, but which are difficult to define and use explicitly - this information is incorporated implicitly in the characterization. A comparison is made between the predicted and observed damage-effective motion characteristics for the Loma Prieta earthquake. The observed analytical characterizations are used to explain specific cases of building damage and non- damage, while the influence of the soil on the motion characterizations is determined statistically. These data from the Loma Prieta earthquake are combined with data computed for earlier events. The project is expected to result in improved statistical formulas for the magnitude/distance/soil dependence of nonlinear damageability. These formulas, when combined with local soils data, are used to conduct probabilistic hazard analyses to derive maps of the damageability of future Bay Area earthquakes.