基于Hoek-Brown强度准则的裂隙岩体劈裂注浆力学机理

摘要

为了获得裂隙岩体中劈裂注浆压力的计算方法,首先假设裂隙岩体服从非线性Hoek-Brown强度准则,采用断裂力学分析模型分析裂隙的劈裂压力,推导裂隙岩体中Ⅱ型和复合型裂纹的劈裂注浆压力计算方法.基于断裂力学中裂纹失稳机制,利用材料的线弹性特性,分析复合型加载条件下裂纹的失稳机制,并提出裂纹扩展的最有可能发展方向.最后,对非线性强度参数及裂纹长度对劈裂注浆压力的影响进行分析.研究结果表明:劈裂注浆压力的计算应该重点考虑裂纹长度和非线性强度参数的影响；裂纹长度对注浆压力的影响显著,注浆压力随裂纹长度增大呈非线性减小;注浆压力随非线性参数的增大而逐渐减小,随地质强度的增大呈先增大后减小的趋势.%The design methods of fracture grouting pressure in fractured rock were gained based on the Hoek-Brown yield criterion and fracture mechanics analysis model.The design methods of fracture grouting pressure in fracture rock for Ⅱ and compound crack were gained.The most likely development of crack instability for complex loading conditions was proposed based on the elastic mechanical properties and fracture mechanics.Finally,the influence of nonlinear strength parameters and crack length on fracture grouting pressure was analyzed.The results show that the effect of nonlinear strength parameters and crack length should be considered the emphasis of consideration in design.Crack length significantly influences fracture grouting pressure.Fracture grouting pressure decreases with the increase of crack length or nonlinear strength parameters.And fracture grouting pressure first increases then decreases with the increase of geological strength index.