基于统一强度理论的破裂围岩劣化弹塑性分析

Deterioration elasto-plastic analysis of cracked surrounding rocks based on unified strength theory

基于深部岩体良好的塑性变形能力和高地应力下瞬时破坏特性,建立了适用深部岩体力学行为的弹塑脆性模型。针对长的圆形巷道,将巷道围岩分成破裂区、理想塑性区和弹性区,同时考虑中间主应力和破裂区围岩弹性模量劣化的影响,采用统一强度理论进行非关联弹塑性分析,获得了围岩应力场和变形场的解析解。并通过补充围岩破坏条件获得了确定围岩破裂半径和塑性半径的解析式。最后结合算例,分析了中间主应力、破裂区围岩弹性模量劣化程度对破裂区范围和围岩变形的影响。

Based on the feature of higher plastic deformation capacity and rapid destruction under high in-situ stress in deep rocks,the elastic-ideal plastic-brittle model suitable for deep rock mechanical behavior was established.For a long and circular mine opening,the surrounding rocks were divided into three regions,i.e.the cracked region,the plastic region and the elastic region.With unified strength theory,considering the action of the intermediate principle stress and the elastic modulus deterioration of the cracked surrounding rocks,the mechanical behavior of the surrounding rocks was simulated by an elasto-plastic model.The closed-form analytical solutions for the stress field and deformation field in the three regions were derived in a theoretically consistency way by using a non-associated flow rule.According to the additional conditions that the surrounding rocks turns out to be cracked,the computational formulae to determine the radii of cracked and plastic regions were obtained.Finally,an example was analyzed to show the influence of intermediate principle stress and the elastic modulus deterioration degree of cracked rocks on the range of cracked region and the deformation of the surrounding rocks.