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松软破碎岩体的复杂力学特性给深部开采工程带来一系列棘手的问题,深入研究破碎岩体峰后力学行为,对于深部巷道围岩稳定性分析及支护结构设计具有重要意义。基于量化GSI围岩评级系统及连续介质理论,建立了考虑围压影响的破碎岩体峰后应变软化力学模型。通过工程应用实例验证了数值模型的可靠性。研究结果表明:通过计算围岩与支护结构相互作用关系可知,理想弹塑性模型和应变软化模型所得计算结果差异较大,采用理想弹塑性模型进行支护设计,可能导致支护结构的安全性偏低,甚至失稳。现场应用结果表明:数值计算结果与现场实际情况吻合;提出的深部破碎岩体应变软化模型能够较为真实地反映破碎岩体的非线性破坏行为,可为硐室围岩稳定性分析及支护结构设计等提供新的思路。
The complicated mechanical properties of loose broken rock mass bring a series of thorny problems to deep mining engineering. It is of great significance to deeply study the mechanical behavior of rock mass after broken peak for the analysis of surrounding rock stability and the design of supporting structure. Based on the quantitative GSI surrounding rock grading system and continuum theory, a post-peak strain softening mechanical model of fractured rock mass considering confining pressure is established. The reliability of the numerical model is verified by engineering examples. The results show that the calculated results of the ideal elasto-plastic model and the strain softening model are quite different by calculating the interaction between the surrounding rock and the support structure. The design of the support with the ideal elasto-plastic model may lead to the safety of the support structure Low, or even instability. The field application results show that the numerical results are in good agreement with the actual conditions in the field. The proposed strain softening model of deep crushed rock mass can reflect the nonlinear failure behavior of the crushed rock mass more truly and can be used to analyze the stability of surrounding rock and support structure Design, etc. to provide new ideas.