LIQUEFACTION MECHANISMS OF SANDY GROUND UNDER COMBINED EARTHQUAKE MOTIONS AND THEIR PREDICTION AND THE STABILITY OF COUNTERMEASURES

Abstract

 The present study investigated the processes of liquefaction of sandy ground under combined earthquake motions involving main shock, calm period and after shock. The experimental results demonstrate three distinct liquefaction mechanisms associated with the upward and downward progress of liquefied zones and the decrease of lateral stresses. A numerical framework considering the propagation and dissipation of excess pore pressures has been constructed and verified aginst the experimental results. The stability of the improved ground to the combined earthquake motions and under elapsed time has also been examined. The results obtained may effectively contribute to the evaluation, prediction and countermeasures of the liquefaction risk under combined earthquake motions.