Performance of Earth Dams During the Whittier Narrows Earthquake of October 1, 1987

一批土石坝， 运动记录仪，经历了惠蒂尔海峡地震， 1987年10月1日 距离最近的是惠蒂尔海峡大坝， 距离震中100公里。 最大 水平加速度为0.32g， 而上游的记录器显示， 0.46g. 在更远距离的其他水坝的反应也是如此。 得到了 很少有强震记录可用于这样的 结构. 这个项目的目的是分析这些记录从九个地球 为了了解土坝的行为， 不同分析模型在大坝分析中的应用 反应 主震时的震动，以及之后的震动 冲击，触发了九个大坝上的所有加速仪， 最广泛的土坝地震反应测量阵列 在美国和国外都有。 这是一个合作项目 加州理工学院和大学之间 南加州。 主要有三项工作：（1）数据处理、分析， 和比较的加速度记录;（2）评价 大坝内部永久变形和裂缝;（3） 在一份报告中总结了观察结果、结果和结论， 加强土坝的一般建议 抗震性能 加州理工学院是 集中进行物理模型离心试验 一个或两个这样的大坝，而南方大学 加州正在集中精力简化和复杂 九个大坝的数值模型。 正在进行比较， 离心试验的结果，观察到的反应， 惠蒂尔海峡地震期间的大坝，以及 利用数值模型进行计算机分析。

A number of earth and rockfill dams, instrumented with strong ground motion recorders, experienced the Whittier Narrows earthquake of October 1, 1987. The closest was the Whittier Narrows Dam, at 4 kilometers distance from the earthquake's epicenter. The maximum horizontal acceleration was 0.32g recorded at the crest of the dam, while the upstream recorder indicated a peak vertical acceleration of 0.46g. The response of other dams at greater distances was also obtained. Few strong motion records are available for such structures. This project addresses the analysis of these records from nine earth dams in order to understand the behavior of earth dams, and the utility of different analytical models for the analysis of dam response. The shaking during the main shock, as well as the after shocks, triggered all accelerographs on the nine dams, providing the most extensive array of earthquake response measurements of earth dams yet obtained in the U.S. and abroad. It is a cooperative project between the California Institute of Technology and the University of Southern California. Three major tasks are being addressed: (1) data processing, analysis, and comparison of accelerograms; (2) evaluation of internal permanent deformation and cracking in the dams; and (3) summarizing the observations, results, and conclusions in a general recommendation for the strengthening of earth dams for earthquake resistance. The California Institute of Technology is concentrating on performing centrifuge tests on physical models of one or two of these dams, while the University of Southern California is concentrating on both simplified and complex numerical models of nine dams. A comparison is being made of the results of the centrifuge tests, the observed response of the dams during the Whittier Narrows earthquakes, and the results of the computer analysis using the numerical models.