Seismic deformation analysis of earth dams : a simplified method

Motivated by the dynamic behaviors of two earth dams, named La Villita Dam and El Infiernillo Dam in Mexico, during an earthquake on September 19, 1985, a seismic deformation analysis is elaborated in this study. Firstly, a simplified method is developed by applying a rigid block model to study the major characteristics of an earth dam during an earthquake and calculate the seismic permanent displacements. In this method, the sliding mass is modeled as a rigid body along a well defined surface. Both inclined plane and circular arc slip surfaces are considered. Secondly, in order to validate the numerical procedure of the simplified method and study the dynamic response of the rigid block on an inclined plane experimentally, shaking table tests are performed on the model used in the simplified method. Comprehensive numerical simulations are carried out with the computer programs developed, and comparisons with the test results are made. Finally, applying the developed method to La Villita Dam and El Infiernillo Dam, seismic deformation analyses are carried out. In addition, an attempt to reproduce some of the motions recorded on La Villita Dam during the 1985 earthquake is made in this study