为得到清水营煤矿近距离煤层开采过程中,破断顶板层结构的形成、运动规律及能量演化特征,结合矿井地质资料,构建二维物理相似模型试验平台,基于全站仪、千分表、热红外成像等技术进行综合监测,并对破断顶板层结构形成的诱因及其扩展发育特征进行理论分析,得出近距离煤层下行开采过程中,二煤开采对其底板的破坏深度达10.05 m;三煤开采对上覆破断岩层造成二次扰动,覆岩整体下沉量为0.39 m,破断顶板层发育高度达到21.9 m;提出破断顶板层结构扰动下支架载荷由静态载荷与动态载荷构成,为保证工作面支护强度,需提高支架的工作阻力和初撑力;针对松散破断顶板层可采取工作面挂网作人工假顶、预注水泥砂浆固化顶板等方式提高顶板结构的完整性和承载力。
In order to study the formation,movement,and energy exchange of the broken roof in the process of mining contiguous seams,a two-dimensional physical simulation model was built. Based on integrated monitoring of total station instrument,dial gauge and thermal infrared imagine,as well as theoretical analysis the causes of broken roof structure and its characteristics of rock mass development. The results show that during downward mining in close-distance seams,the damage depth to the secondary seam is 10.05 m; mining the third coal seam will caused induced disturbance on the stability of the strata,and subsidence amount is 0.39 m; the height of broken roof seam is 21.9 m. The conclusion is made that the load of support is composed of static load and dynamic load when disturbance from broken roof structure is at present. To ensure the support strength at the working face,the support resistance of the hydraulic support and setting load should be increased. To improve the integrity and bearing capacity of broken loose layer,an artificial roof can be made by applying steelwire reinforcement,or pre-grouting to stabilize and solidify the roof.