考虑中间主应力影响的土中孔扩张问题精确相似解

Rigorous similarity solution of cavity expansion in soil taking the effect of intermediate principal stress into account

由于莫尔库仑模型不能考虑中间主应力对材料屈服的影响,本文使用双剪统一强度理论,考虑中间主应力的影响,并同时考虑土体的剪胀和应变软化特性,给出了柱孔或球孔扩张问题的精确相似解答。算例表明,中主应力对计算结果影响显著,与不考虑中主应力影响结果相比,考虑中主应力影响时塑性区半径明显减小,极限扩张压力明显增大,同时土的应变软化和剪胀特性对相似解结果也有很大影响。

The twin-shear united strength theory is applied to deduce the rigorous similarity solution of cavity expansion in soil.The effect of intermediate principal stress is taken into account.At the same time, the dilation and strain softening effects of soil are also considered.The calculation of an example shows that the effect of intermediate principal stress is remarkable.The radius of plastic area is greatly decreased and the limit expansion pressure is greatly increased, if the effect is taken into account.Besides, the dilation and strain softening effects will significantly affect the result of similarity solution.