考虑工程扰动和地质条件的巷帮极限平衡区分析

基于Hoek-Brown和Mohr-Coulomb强度准则,建立了与工程扰动程度D、岩体地质强度指标GSI相关的非线性岩体强度参数(内摩擦角、黏聚力)表达式,分析了参数D,GSI对内摩擦角和黏聚力的影响变化规律。以巷帮煤岩体处于完整与破碎两种极端条件为例,基于提出的非线性M-C准则,建立了与参数D,GSI有关的巷帮滑移面正应力和极限平衡区宽度方程式,并研究参数D,GSI对极限平衡区的影响。结果表明:参数D越小、GSI越大时,内摩擦角与黏聚力越大,说明岩体完整性越好,非线性岩体强度参数值越大;巷帮滑移面正应力随参数D的增大而减小,随参数GSI的增大而增大;极限平衡区宽度随参数D的增大而增大,随参数GSI的增大而减小。最后,通过工程实例分析,验证了研究成果的合理性。

Analysis of limit equilibrium zone for roadway side wall considering engineering disturbance and geological condition

To analyze the change law of the influences of parameters D and GSI on internal friction angle and cohesion,the formula of nonlinear rock strength parameters (internal friction angle and cohesion),related to the extent of engineering disturbance (D) and rock geological strength index (GSI),was proposed based on the Hoek-Brown strength criterion and Mohr-Coulomb strength criterion.Coal and rock under intact and crushed condition was taken as an example,the equations of both normal stress over slip plane and the width of the limit equilibrium zone for roadway sidewall,associated with parameters D and GSI,were established based on the proposed nonlinear M-C criterion.Influences of both D and GSI on the limit equilibrium zone were studied.The results show that the smaller the parameter D,the greater the GSI,the greater the angle of internal friction and cohesion,which denotes that the better rock mass integrity,the greater the value of nonlinear rock strength parameters.The normal stress over slip plane of roadway sidewall decreases with the increase of parameter D,increases with the increase of parameter GSI.The width of limit equilibrium zone increases with the increase of parameter D,decreases with the increase of parameter GSI.Finally,through the analysis of a project case,the research results are verified to be reasonable.