La Villita Dam Response during Five Earthquakes including Permanent Deformation

Abstract

La Villita is a 60 m high earth and rockfill dam located 350 km southwest of Mexico City, Mexico. Since its construction the dam has been subjected to six major earthquakes, of which five are believed to be responsible for significant localized deformation in the dam. The dynamic response of the dam to these shaking events was recorded by a strong‐motion instrument located near the crest on a portion of the dam, which appears to move as a sliding block. In addition, permanent displacements after each earthquake were recorded and documented. In this investigation, it is found that the strong‐motion records not only indicate localized deformations (partial incremental failure) but also reveal the magnitude of the associated yield acceleration. The present analysis may lead to an increased understanding of the response of structures where stick‐slip‐type deformations take place.