基于实测地应力的综放工作面采动应力分布及演化特征研究

Mining-induced stress distribution and its evolution in fully mechanized top-coal caving face based on in-situ stress

基于地应力对综放工作面煤岩体变形破坏、动力灾害防治、采动应力场演化等的重要影响,在朱仙庄煤矿南翼地应力实测的基础上,开展了基于多目标约束的矿井应力场最优化反分析,获得了矿区最优边界荷载和地应力分布规律。利用FLAC^(3D)建立数值模型,探讨了最大主应力与工作面推进方向夹角α、侧压系数λ及水平应力非均匀系数ζ等因素对综放工作面采动应力场的影响规律。结果表明:不同地应力对综放采场内各采动应力场分布及演化特征具有显著影响。针对该矿井某一实际工作面的地应力分布特征、煤岩物理力学参数及开采技术条件,分析了综放面采动应力场的分布规律及其随工作面推进的演化特征。研究结果可为综放工作面的顶底板管理、巷道支护等提供重要借鉴。

Value and orientation of in-situ stress play an important role in surrounding rock deformation, dynamic disaster and mining-induced stress field around the fully mechanized top-coal caving（FMTC） face, which was always little considered in the past related research work. The hollow inclusion strain gauge method was used to measure the in-situ stress in the south limb of Zhuxianzhuang（ZXZ） coal mine, and the original ground stress field has been feedback analyzed based on multi-objective constraints optimization method, while the results illustrate the optimum boundary loads and in-situ stress distribution. In addition, numerical models with FLAC^（3D）have been established to investigate the influence law of mining-induced stress redistribution characteristics in FMTC mining face by the factors of the intersection angle between the longwall panel advancing direction and the maximum stress direction, the non-uniform coefficients of horizontal stress, and the lateral pressure coefficients, and so on. The results indicate that in-situ stress states has remarkable effect on mining-induced stress distribution and evolution characteristics of FMTC mining face. Finally, based on the real in-situ stress state, physical and mechanical parameters of coal-rock mass, and mining conditions of a coal face in ZXZ coal mine, the mine-induced stress distribution rules and its evolution process were further analyzed. Research results show that superposition and interaction of mining-induced stress and in-situ stress are important for strata management and roadway support in similar FMTC mining face.