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在高应力和复杂的地质环境中,深部球形洞室围岩在开挖扰动下会出现破裂区和非破裂区交替出现的分区破裂化现象,研究分区破裂化现象可以深化深部岩体的力学性能研究,同时对深埋洞室的开挖和支护设计提供理论基础。该文研究的深部球形洞室外部受到静水压力的作用,洞室内壁受到一个随时间变化的开挖荷载的作用,其运动方程用位移势函数来表示。通过Laplace变换简化计算,获得势函数的通解,从而获得了在开挖扰动下洞室围岩的应力场和位移场。当围岩应力场满足深部岩体强度准则时,岩体破裂,从而产生变形局部化。岩体破坏产生的应力重分布可能导致新的围岩破坏,从而产生二次破裂区;以此类推,直到应力释放后不能产生破裂区为止。根据断裂力学确定破裂区的残余强度,并确定破裂区和非破裂区的宽度和数量。破裂区的形成受到岩体力学性能、洞室开挖方式和速度等较大的影响。
In high stress and complex geological environment, the surrounding rock of deep spherical caverns will appear the phenomenon of zonal disintegration alternately in rupture zone and non-rupture zone under the disturbance of excavation. Studying the phenomenon of zonal disintegration can deepen the mechanical performance of deep rock mass Research, at the same time provide a theoretical basis for the excavation and support design of deep caverns. In this paper, the hydrostatic pressure is applied to the exterior of the deep spherical chamber. The inner wall of the chamber is subjected to a time-varying excavation load. The equation of motion is expressed by the displacement potential function. The Laplace transform is used to simplify the calculation and the general solution of the potential function is obtained. The stress field and displacement field of the surrounding rock are obtained under disturbance of excavation. When the surrounding rock stress field to meet the deep rock mass strength criteria, the rock mass ruptures, resulting in deformation localization. The stress redistribution caused by the failure of the rock mass may lead to the destruction of the new surrounding rock, resulting in the secondary rupture zone, and so on until the rupture zone can not be formed after the stress is released. The residual strength of the rupture zone is determined according to the fracture mechanics and the width and number of the rupture zone and the non-rupture zone are determined. The formation of the rupture zone is affected by the mechanical properties of the rock mass, the way of excavation and the speed of the cavern.