Liquefaction Analysis for Multidirectional Shaking

A method of analysis is presented for the evaluation of the seismic response and liquefaction of horizontally-layered level ground under multidirectional shaking. A new material model is introduced for representing the behavior of sand under cyclic biaxial shear stresses. The responses to multidirectional shaking are demonstrated through a series of case studies. These case studies were performed by using a new computer program LASS-III which was developed for analysis of multi-directional shaking of horizontally-layered ground. The results of a number of analyses are presented in which the influence of the vertical component base acceleration and the interaction between the two horizonal components of shaking are evaluated.