基于离散元法的静止土压力系数分析

发布时间：2019-01-11 10:26

【摘要】：采用三维离散元法(DEM)对不同初始孔隙比的粒状土进行一维压缩0K试验模拟。对比了传统定义静止土压力系数0K以及增量型定义静止土压力系数0K?,分析了静止土压力系数的影响因素(初始应力状态、初始孔隙比和应力历史),检验了Jaky公式及Mayne和Kulhawy公式的适用性。结果表明,对于初始等向围压试样,随着竖向压力的增大,0K减小,则0K?先增大到峰值后再减小;对于初始0K状态试样,0K、0K?随着竖向压力的增大均减小。0K、0K?分别在竖向压力达到初始等向围压6~10倍及4倍左右达到稳定值,即真实的0K值;0K、0K?随孔隙比减小而明显减小。应力历史对0K有显著影响,对于相同应力状态的加载和卸载阶段0K差别很大。Jaky公式及Mayne和Kulhawy公式计算结果与数值模拟结果有一定差异,采用峰值摩擦角比采用残余摩擦角的公式计算结果更接近数值模拟结果。
[Abstract]:Three-dimensional discrete element method (DEM) was used to simulate the one-dimensional compression 0K test of granular soil with different initial void ratios. In this paper, the influence factors of static earth pressure coefficient (initial stress state, initial void ratio and stress history) are analyzed by comparing the traditional definition of static earth pressure coefficient 0 K with that of incremental definition of static earth pressure coefficient 0 K. The applicability of Jaky formula and Mayne and Kulhawy formula are tested. The results show that with the increase of vertical pressure, 0K decreases, then 0K? For the initial 0K state sample, 0K / 0K? The vertical pressure decreases with the increase of vertical pressure. When the vertical pressure reached the initial isotropic confining pressure of 6 ~ 10 times and 4 times, respectively, it reached a stable value, that is, the true value of 0 K, the value of 0 K, and the value of 0 K ~ 0 K? With the decrease of void ratio, it decreases obviously. The stress history has a significant effect on 0K, and for the loading and unloading stages of the same stress state, 0K is very different. The calculation results of Jaky formula, Mayne and Kulhawy formula are different from those of numerical simulation. The calculated results by using the peak friction angle are closer to the numerical simulation results than by the residual friction angle formula.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;
【基金】：国家重点基础研究发展计划(No.2012CB719803) 国家自然科学基金(No.51308408,11372228)
【分类号】：TU432

【共引文献】