各向异性初始应力状态下圆柱孔扩张理论弹塑性分析

传统的圆柱孔扩张理论假定初始应力为各向同性的。在城市地下管道的铺设、隧道工程等的水平掘进施工过程中，圆柱孔受到的初始竖向应力不等于初始水平应力，并不满足各向同性初始应力条件。考虑土体的各向异性初始应力条件，假定土体满足Mohr-Coulomb屈服准则，推导了各向异性初始应力状态下的圆柱孔扩张问题弹塑性解答。算例计算结果表明：土性参数一定时，在相同内压力作用下，各向异性初始应力状态下的圆柱孔扩张形成的塑性区半径大于各向同性初始应力状态下的圆柱孔扩张的塑性区半径，但前者的极限扩孔压力小于后者。

Elastoplastic analysis of cylindrical cavity expansion with anisotropic initial stress

Traditional cylindrical cavity expansion theory is based on the isotropic initial stress supposition. However, the cylindrical cavity is usually expanded in case of horizontal initial stress unequal to vertical initial stress, such as the horizontal directional drilling in tunnel engineering. A new elastoplastic cylindrical cavity expansion solution is introduced, in which the anisotropic initial stress is explicitly considered. Case study results indicate that the cylindrical cavity expansion with anisotropic initial stress yields a larger plastic zone than that with isotropic initial stress when the rest geometrical and geomaterial parameters are the same. The results also demonstrate that the cylindrical cavity expansion with anisotropic initial stress results in a smaller ultimate expansive pressure than that with isotropic initial stress.