综放工作面及其围岩宏观应力壳力学特征

采用大型非线性三维计算机数值模拟、实验室相似材料模拟对综放工作面围岩应力分布进行了深入研究，发现综放工作面围岩存在高应力束组成的宏观应力壳，应力壳位于采场四周未采煤岩体和弯曲带内，其形态随工作面推进采场结构的变化而改变.应力壳承担并传递上覆岩体荷载和压力，是最主要的承载体，应力壳拱脚处应力形成采场四周围岩支承压力.砌体梁结构位于宏观应力壳下的减压带内，砌体梁仅承担壳体下岩层部分荷载.综放工作面主要力学特征是位于上覆围岩宏观应力壳保护下的低应力区内，这正是综放工作面矿压显现趋于缓和的根本原因.基于对应力壳体的发现和开展的一系列分析，揭示了综放采场顶煤“垫层”作用的力学本质.

Mechanical characteristics of fully mechanized top-coal caving face and surrounding rock stress shell

The distribution of surrounding rock stress in fully mechanized top-coal caving (FMTC) face was fully researched by large-scale and non-linear three-dimensional numerical simulation and equivalent material simulation. The results show that,there is the structure that is made up of macroscopical stress shell composed of high stress binds in overlying strata of FMTC face. Stress shell lies in virgin rock mass in the vicinity of working face and sagging zone, and the shape will transform with the variation of working face structure. Stress shell, which bears and pass load of overlying strata, is primary supporting body. The stress in skewback of stress shell forms abutment pressure of surrounding rock in vicinity of working face. Bond-beam structure lies in reducing zone under stress shell. It only bear partial burden of strata under stress shell. The uppermost mechanical characteristic of FMTC face is lying in the low stress area under stress shell. It is essential cause of strata behaviors of FMTC face relaxation, as well as. On the basis of analyzing stress shell, the mechanical essence that top coal performs a function of bedding is demonstrated.