不同重力场下静力触探试验离散元数值分析

采用离散元商业软件PFC2D对7种重力场下静力触探试验进行了对比分析试验，以研究高、低重力场下静力触探试验的异同点。数值试验结果表明：不同重力场下土体受静力触探贯入主要影响区域不同，低重力场下主要是上部土体受到影响，高重力场下主要是下部土体受到影响；归一化贯入阻力的最大值和稳定值、归一化球应力和偏应力的最大值均与重力加速度的倒数呈线性关系，均随重力加速度倒数的增加而增大；土体经历了明显的加载、卸载过程，重力加速度越小，加载、卸载现象越明显，同一重力加速度下上部土体加载、卸载程度大于下部土体。

Numerical analysis of cone penetration tests under different gravity fields by distinct element method

The cone penetration tests under seven different gravity fields were studied by a commercial distinct element method (DEM) code PFC2D (particle flow code) in order to investigate the relationship between cone penetration tests under high and low gravity fields. The numerical results show that cone penetration has an apparent effect on the upper zone of the ground under low gravity fields, while it has a significant effect on the lower zone of the ground under high gravity fields. The maximum (steady) values of the normalized cone tip resistance and the maximum values of normalized mean stress and deviatoric stress increase linearly with the reciprocal of gravity accelerations. The soil around the penetrometer undergoes apparently loading and unloading process during the penetration process, with the smaller gravity field corresponding to the more apparent loading and unloading phenomenon, while the upper zone of the ground undergoes the loading and unloading process more apparently than the lower zone under the same gravity field.