Numerical simulation of liquefaction behavior on gravelly soil in dynamic triaxial test by particle flow code

In order to analyze the liquefaction mechanism of saturated gravelly soil, a discrete element simulation analysis method for different particle grading soil samples and a subprogram for statistical analysis of meso-fabric parameters are developed according to the discrete characteristics of multi-scale granular mixtures. The liquefaction behavior of saturated sand gravel in dynamic triaxial test is simulated by using the constant volume cyclic biaxial numerical test with Particle Flow Code. The evolution regularity of meso-scopic fabric parameters including average coordination number, fabric distribution in the liquefaction progress are obtained. Results show that the numerical simulation can reflect the general characteristics of liquefaction behavior of saturated gravelly soil in dynamic triaxial test. Macroscopically, liquefaction on saturated gravelly soil is manifested by effective stress decline and accumulation of dynamic pore pressure, and microscopically, it is manifested by reduction of average coordination number. The fabric distribution can reflect the deflection direction of the principal stress.