PARAMETER SETTING STUDY ON NONLINEAR DYNAMIC EFFECTIVE STRESS ANALYSIS OF LIQUEFACTION RESISTANCE OF VERY DENSE DILUVIAL SAND

Abstract

 The soft ground consisting of the saturated alluvial sand deposit is usually examined for the soil liquefaction potential. Due to the recent increase in seismic design force, the liquefaction resistance of very dense diluvial sand is also sometimes required for the seismic-assessment of the important structure. It is confirmed that the frozen sample has different liquefaction characteristics from a liquefiable sand material in the laboratory test. Under undrained cyclic shear loading, the shear strain increased and the excess pore water pressure did not increase. We analyzed the characteristics on the basis of the simulant material experiment and the numerical simulation. By using the reconstituted soil-cement mixture, we conducted a uniaxial compression test and a cyclic torsional shear test on hollow cylindrical specimen, and confirmed the similar liquefaction characteristics. In addition, we were able to simulate numerically the characteristics by parameter setting of a strain space multiple mechanism model introduced into the effective stress finite element method.