Studies of Soil Liquefaction Resulting from the April 22, 1991 Costa Rica Earthquake

1991年4月22日发生在哥斯达黎加的地震引发了广泛的地面破坏：土壤液化和蔓延；由于土壤液化而导致的桥台基础坍塌；以及山体滑坡。人们对液化引起的地面破坏知之甚少，因此，只有粗略的标准来预测它们的发生和这些事件的破坏能力。哥斯达黎加最近发生的地震提供了一个意想不到的机会，可以进行详细的实地观察和测量，从而形成一套有充分记录的病例记录。这类案例有助于理解地面故障过程；它们还为验证分析和经验预测模型提供了基准事件。这一研究项目的主要目标是在哥斯达黎加的几个液化引起的地面破坏场地进行详细的地形和地面位移测量。要测量的地表效应是很快就会消失的特征。

The April 22, 1991 earthquake in Costa Rica triggered widespread ground failures: soil liquefaction and spreading; foundation failure of bridge abutments due to soil liquefaction; and landslides. Liquefaction-induced ground failures are poorly understood, and as a consequence, only crude criteria have been developed for predicting their occurrence, and the destructive capability of these events. This recent earthquake in Costa Rica provides an unexpected opportunity to make detailed field observations and measurements, resulting in a well-documented set of case histories. Such case histories aid in understanding the ground failure process; they also provide benchmark events for verification of analytical and empirical predictive models. The principal objective of this research project is to make detailed topographic and ground displacement measurements at several liquefaction-induced ground-failure sites in Costa Rica. The ground surface effects to be measured are features that will soon disappear.