针对非脆性软化剪胀土中柱形孔扩张问题,将摩擦黏性土体损伤后的软化特性用材料的力学性能参数下降来描述,引入了损伤软化参数.同时考虑土体的剪胀与内摩擦角、黏聚力以及平均应力的相关性和软化特性对应力一剪胀关系的影响,采用了引进损伤软化参数的Rowe流动法则,并结合利用反映中间主应力效应的广义空间准滑动面理论和平面应变轴对称问题柱形孔扩张基本方程,推导并给出摩擦黏性土中大应交柱形孔扩张曲线的数值求解步骤.通过算例分析,将所得解与Mohr-Coulomb破坏准则的解答进行了比较,研究了中主应力效应的特性,并且探讨了损伤软化参数、内摩擦角及黏聚力对极限扩孔压力、塑性区半径、塑性区应力场、平均剪胀等的影响.
In order to make an analysis of cylindrical cavity expansion in cohesive-frictional soil with non-brittle softening behavior, damage softening parameter that represents degradation grads of material mechanics capacity is introduced into Rowe~s stress-dilatancy relation accordingly considering soil softening behavior and dilatancy related to friction angle, cohesion and mean stress. Based on the combination of stress-dilatancy relation with the extended spatial mobilization plane (SMP) theory involving the effect of intermediate principal stress and the governing equations of axisymmetric cylindrical cavity expansion in the plane strain condition, the numerical procedure of pressure-expansion process with large strain is proposed. A comparative study is made for the present solution and current solution based on Mohr-Coulomb criterion to display the effect of intermediate principal stress. Also the influence of damage parameter, cohesion and friction angle on limit cavity pressure, plastic radius, stress distribution and average dilataney of plastic zone is examined.