高频循环剪切下密砂与结构接触面土体性状的颗粒离散元分析

Behavior of Dense Sand-structure Interface Undergoing the High Frequency Cycle Shearing

采用颗粒离散元方法,分析了高频循环剪切荷载下密砂与结构接触面的土体性状性,从不同的颗粒因素和剪切条件来分析接触面土体孔隙率、体应变以及典型位置颗粒的变化情况。数值模拟结果表明,密砂颗粒摩擦系数越大、其剪胀性越弱;颗粒刚度越大,其剪胀性越强;密砂的颗粒刚度比对其力学性质影响不大;边界围压越大,密砂的剪胀性越弱;高频循环剪切的剪切振幅越大,其剪胀性越强;剪切频率对其剪胀性规律不明显。

The behavior of dense sand-structure interface undergoing the high frequency cycle shear was studied by Particle Discrete Element Method（DEM）.The change of the porosity sand and volumetric strains were examined in detail.The results showed that the dilatation of sand is less obvious with the increase in the particle friction coefficient of dense sand.The larger the dense sand particle stiffness is,the stronger the sand dilatation becomes.The particle stiffness ratio has a little effect on the mechanical properties of sand.In addition,the increase in volume of sand under shearing is not obvious with the increase of the confining pressures.Moreover,the increase in sand shear dilatation under shearing is greater with the increase in the high frequency cycle shear amplitude.The sand shear dilatation is not affected by the shear frequency.