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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。
One-dimensional compression 0K experiment was performed on three-dimensional discrete element method (DEM) for granular soils with different initial void ratios. Compared with the traditional definition of static earth pressure coefficient 0K and incremental definition of static earth pressure coefficient 0K ?, the influencing factors of static earth pressure coefficient (initial stress state, initial void ratio and stress history) are analyzed. The Jaky’s formula and Mayne’s Applicability of Kulhawy formula. The results show that for the initial equal confining pressure specimen, 0 K decreases first and then decreases with the increase of vertical pressure, Vertical pressure increases are reduced. 0K, 0K? Respectively, the vertical pressure reached the initial confining pressure of 6 to 10 times and about 4 times to reach a stable value, that is, the true value of 0K; 0K, 0K? With the porosity decreased and significantly reduced. Stress history has a significant effect on 0K, 0K for the same state of stress loading and unloading vary greatly. The results of Jaky formula, Mayne and Kulhawy formula are different from those of numerical simulation. The results of numerical simulation using the formula of the peak friction angle is more approximate than the formula of the residual friction angle.