Slope Stability During Earthquakes

Catastrophic slops failures, which have occurred during medium and large earthquakes, illustrate the need for development of reliable methods for anticipating and preventing such failures. Unfortunately there is an insufficient backlog of adequately documented case histories to provide a reliable basis for quantitative evaluations based on past experience and pseudostatic methods of analysis leave much to be desired. The limitations of pseudostatic methods are outlined, and recent development relating to dynamic response analyses, investigations of soil behavior under cyclic load conditions, design procedures, and analyses of actual slope failures are described. It is suggested that these developments provide a framework for evaluating previous failures and thereby offer the possibility for a more meaningful categorization of experience and an improved guide to engineering Judgment in the evaluation of slope stability during earthquakes.