轴向高水平应力条件下深部巷道围岩变形机理与破裂演化规律

Due to the facts that the best layout direction of roadway is parallel to the direction of maximum horizonal stress , axial high horizonal stress is normal on conditions of high horizonal stress. It’s not similar to shallow roadway surrounding rock stable control which large deformation and destruction are commonly occurrenced around surrounding rock on deep roadway, the research on law of deformation and cracking is of important theoretical value and engineering significance during the deep engineering amount gradual increasing. On conditions of high horizonal stress,an integrated research method of field measurement, mechanical parameter test, theoretical research, the three axial model test and numerical simulation, etc. is to be applied to innovative key research as follows : (1) the parameters of softening strain and fracturing expansion , law of deformation and characteristic of cracking and suitable constitutive model built, (2) partition model established with deformation and failure around surrounding rock on deep roadway which is different from intermediate principal stress; (3) the whole failure process reproduced on deep roadway by simulation and cracking process storaged and analysised real-time.Through those researches, evolution law of surrounding rock deformation and cracking are to be revealed. The research result will enrich the control theory on roadway surrounding rock under high horizontal stress, develop cognitive of maximum horizontal stress, design the schemes of support and reinforced under those guidance, ensure stability control of surrounding rock around deep roadway, ultimate realize security, economic, efficient mining in deep mine.

在高水平应力作用下，巷道的最佳布置方向是巷道轴向与最大水平主应力方向平行，“轴向高水平应力”现象常见。不同于浅部巷道围岩稳定，此类条件下深部巷道大变形破坏十分普遍，随着深部工程渐增，开展本项目研究具有重要的理论价值和工程意义。本项目拟采用现场实测、力学参数测试、理论研究、真三轴模型试验及数值模拟等综合研究方法，针对轴向高水平应力条件，重点开展以下创新性研究：（1）深部巷道围岩应变软化、碎胀扩容参数及变形破坏特征，构建适合此类巷道的围岩本构模型；（2）建立区别于中间主应力的深部巷道围岩变形破坏分区模型；（3）模拟再现深部巷道变形破坏全过程，实时存储并分析破裂特征。通过综合研究，将揭示此类巷道围岩变形机理与破裂演化规律。研究成果将丰富高水平应力下巷道围岩控制理论，拓展对最大水平应力理论的认知，指导支护及修复加固方案科学合理设计，确保深部巷道围岩稳定，最终实现深部矿井安全、经济、高效开采。

高水平应力赋存是深部巷道开掘的常见应力环境，但在其长轴向与高水平应力一致时，按最大水平应力理论，在浅部时，此种布置形式下巷道围岩变形破坏最为严重，但深部的规律性是否一致值得深入研究。因此，在淮南矿区已有文献记载的深部高水平应力场中，开展了空芯包体应力解除法测试获得深部典型轴向高水平应力赋存状态，同时测试了围岩力学参数特性，构建了应力应变本构关系模型，与此同时钻孔窥视了顶板破坏特征；基于力学参数测试结果，结合弹塑性理论及D-P/H-B强度准则，建立了区别于中间主应力的轴向最大主应力下深部巷道围岩变形破坏分区模型，设计正交实验方案，分析了轴向应力场中采掘扰动、支护力、围岩强度对深部巷道围岩稳定性的影响及其作用程度。真三轴模型试验深入研究部分工况下深部巷道围岩变形机理、“圈形破裂”的演化规律；基于测试的软化模量、扩容梯度，优化FLAC3D算法，构建三维模型反演分析深部巷道围岩应力、位移及弹性、塑性软化、塑性残余分区范围的变化规律。综合前述研究成果，揭示此类条件下巷道围岩变形机理与破裂动态演化规律，提出了轴向高水平应力下深部巷道围岩大变形破坏的科学合理、及时有效的防控对策。