基于综放采场围岩宏观应力壳的发现及其力学特征的分析,采用现场实测、实验室相似材料模拟试验及计算机数值模拟(FLAC3D)综合方法开展留窄煤柱非对称综放开采采场围岩应力壳壳基、壳体应力演化特征、演化形态及演化参数问的关系分析。研究结果表明,应力壳演化是工作面推进过程中采动高应力在围岩空间的动态平衡过程,其演化形态随工作面推进根据采场结构发生变化,非对称开采条件应力壳演化分为旧壳扩展阶段、新壳形成一壳基上提阶段及新旧壳贯通趋于相对稳定3个阶段,应力壳在覆岩空间中的演化形态近似呈半空间椭球壳,揭示应力壳应力演化及其形态特征。研究为采场围岩控制、巷道布置及其围岩控制、瓦斯抽采、安全高效开采等提供理论依据。
A key issue in underground mining is to understand and master the evolving patterns of mining-induced stress, especially abutment pressure, and to control and utilize the action of rock pressure. Based on the mechanical characteristics analyses of macro stress shell(MSS), in-situ observation, numerical and physical modeling tests have been carried out to investigate the redistribution patterns, mechanical characteristics and geometrical parameters of the MSS developing and those correlations in the rock surrounding a fully mechanized top-coal caving (FMTC) face with unsymmetrical disposal. The results show that, with the face advancing, the MSS evolution is bundled of mined-induced high stress developing and recurrently equilibrating process until one new balance forming and the MSS development shape is an approximate half-space ellipsoid shell in overburden strata. The mechanical characteristics of MSS evolution are opened out and the MSS development could be divided into three stages in unsymmetrical disposal with small wide coal pillar, namely the old MSS expanding stage, the new MSS forming stage, and the gradually-correspondingly stabilizing stage. Drastic rock pressure in mine may occur when the balance of the stress shell is destruction or the forces system of the stress shell transfers. This study will pay an active role in theoretic references to rocks stability control, gateway layout, efficiency and safety mining.