Factors influencing the computational determination of earthquake-induced shear stresses in sandy soils

The Simplified Procedure (Seed and Idriss 1971) is frequently used to evaluate earthquake-induced shear stresses in soils. It considers soils as a rigid block and corrects for the effects of deformability by a stress reduction factor, r;The effects of method of response analysis was studied using three different techniques: (1) SHAKE, (2) DESRA and (3) TESS. There was no consistent pattern of influence of the method of analysis on the values of r;The effects of earthquake characteristics were studied in terms of the earthquake magnitude and the predominant period of input motion. An increase in the earthquake magnitude or the predominant period increased the values of r;Site condition can also have a significant effect on the values of r;Based on the results of the studies it was concluded that the best results would be obtained by the use of a magnitude-dependent value of r;In the evaluation of the liquefaction potential of a sandy site it is of great importance that the methods of evaluating the induced cyclic stress ratio and the liquefaction resistance curves are based on the same r...