高应力软岩巷道围岩与支护结构相互作用分析

Analysis of interaction between surrounding rock and support structure in high stressed soft rock roadway

基于Mohr-Coulomb应变软化模型,将收敛-约束法应用于高应力软岩巷道围岩-支护相互作用分析中,构建典型支护结构特征曲线。以FLAC3D数值模拟软件为工具,分析应变软化模型、剪胀角及不同巷道断面类型对围岩-支护相互作用的影响,并对支护系统稳定性进行评价。研究结果表明:考虑应变软化行为的围岩所需支护压力与Mohr-Coulomb模型计算结果相差较大,剪胀角对围岩应力释放过程及围岩-支护相互作用影响较小,巷道不同断面形式及断面不同位置点围岩所需支护压力有一定差异性;初期支护系统的稳定性是围岩与支护系统最终稳定的关键,采用收敛-约束法评价高应力软岩巷道初期支护系统的稳定性,对高应力软岩巷道的支护结构设计及施工具有一定指导意义。

Based on the Mohr-Coulomb strain softening model, applying the convergence confinement method to analyze the interaction of surrounding rock and support in high stressed soft rock, the characteristic curves of the typical support structure are constructed. Using the FLAC3D numerical simulation software to analyze the influencing factors of interaction of surrounding rock and support, such as strain softening model, dilatancy angle, different roadway types; and then the stability of support system is analyzed. The results show that： considering the strain softening behavior of the surrounding rock required support pressure are quite different with the calculation results of the conventional elastoplastic model; the dilatancy angle is less impact on the rock stress release process and the interaction of surrounding rock and support; the surrounding rock of roadway which required the support pressures are different in different sections and section points. The stability of the initial support system is the ultimate key to the stability of surrounding rock and support systems; using convergence confinement method to evaluate the stability of early support system of high stressed soft rock. The results have guiding significance for the supporting structural design and construction of high stressed soft rock roadway.