深井无巷旁充填切顶卸压沿空留巷围岩结构稳定性及其协同控制

Coal mining to the deep is an inevitable trend, gob-side entry retaining without pillar mining technology is a development trend in scientific mining, no gateside pack top cutting pressure-relief of gob-side entry retaining cancel the gateside pack, is conducive to reducing the difficulty of gob-side entry retaining and support costs, and improves the safety of production reliability. At present, there are few theoretical studies on the basic theory of top cutting pressure-relief of gob-side entry retaining. The following innovative researches are preformed out by means of laboratory test, numerical simulation, physical simulation and theoretical analysis: (1) The study reveals the characteristics of the stress environment and its perturbation effect of the surrounding rock of gob-side entry retaining before and after top cutting pressure-relief ，and the supporting mechanism of top cutting pressure-relief of gob-side entry retaining with no gateside pack.(2) The study researches the dynamic evolution characteristics of the structural stability of the surrounding rock , constructs structural mechanics model of gob-side entry retaining in different stages, constructs the criterion of the instability of the surrounding rock structure , determines the main controlling factors influencing the stability of the surrounding rock,obtains the interaction and coordination between the surrounding rock and the supporting system, reveals the large deformation control mechanism of the surrounding rock. (3) The principle of stable synergetic control of surrounding rock structure in different stages of the top cutting pressure-relief of gob-side entry retaining are purposed, and establishes the synergetic control system of "pressure relief and auxiliary support". The research results provide the basic theoretical basis for the scientific design of the key parameters of top cutting pressure-relief of gob-side entry retaining and the supporting parameters of the surrounding rock in different stages, and have broad application prospects.

煤矿向深部开采是必然趋势，沿空留巷无煤柱开采技术是科学采矿的发展方向，无巷旁充填切顶卸压沿空留巷取消巷旁充填体，有利于降低沿空留巷难度和支护成本，并提高安全生产可靠性，但目前系统研究切顶卸压沿空留巷基础理论的极少。通过实验室试验、数值模拟、物理模拟及理论分析等综合方法，开展以下创新性研究：（1）研究顶板切落前后沿空留巷围岩应力环境变化特征及其扰动效应，揭示无巷旁充填切顶卸压沿空留巷支护机理；（2）研究围岩结构稳定性动态演化特征，构建不同阶段沿空留巷结构力学模型，提出围岩结构失稳判据，确定影响围岩结构稳定的主控因素，获得切顶卸压沿空留巷围岩与支护系统的相互作用与协调关系，揭示围岩大变形控制机理；（3）提出切顶卸压沿空留巷不同阶段围岩结构稳定协同控制原则，建立“卸压为主、支护为辅”的协同控制体系。研究成果为科学设计沿空留巷切顶关键参数与不同阶段的围岩支护参数提供基础理论依据，具有广阔应用前景。

基于深井切顶留巷围岩结构稳定及其协同控制问题，通过数值模拟研究了不同应力环境下沿空留巷围岩变形及应力分布，发现切顶能够优化留巷围岩应力环境。以巷道直接顶与基本顶层间错动为判据，基于留巷顶板主动支护(锚杆)剪切强度为临界指标，分析了主动支护与临时支护阻止顶板层间错动的量化参数，分析了不同埋深条件下主动支护与临时支护对顶板变形的控制作用，揭示切顶留巷支护机理。.通过平面相似模拟试验研究并得出了切顶线以下岩层在留巷期间呈悬臂梁的“小结构”，采用三维相似模拟试验平台研究得出了切顶线上覆岩层呈砌体梁的“大结构”，利用二维四面加载相似模拟平台研究了底板结构，得出切顶留巷一次采动期间底板呈非对称“ ”结构。建立了留巷围岩“大、小结构”模型，并对结构稳定性及其主控因素进行了分析，得到了切顶留巷顶、底板变形计算表达式。通过深井切顶留巷支护机理、关键参数及围岩结构稳定性研究，获得了深井切顶留巷协同控制原则，针对切顶留巷不同阶段给出了围岩控制方法，并得到了协同控制技术体系。研究成果分别在祁东煤矿7135工作面回风巷、恒源煤矿II632工作面运输顺槽进行了工程验证，取得了良好的技术经济效益，研究成果应用前景广阔。