大采高工作面覆岩空间结构变化矿压显现规律研究

为研究工作面回采过程中,在经历不同的采空边界条件下,工作面不同覆岩空间结构变化及对矿压显现的影响,基于理论计算、微震监测、应力在线监测等方法,对母杜柴登煤矿30202工作面回采期间所形成的不同覆岩结构类型进行分析,得到不同覆岩空间结构下强矿压显现特征及危险区分布规律。研究结果表明：30202工作面回采过程中,先后经历“一面为自身采空区,三面为实体煤”到“两面为采空区,两面为实体煤”的边界条件,其覆岩空间结构相应的会经历“O”型、“O-S”型到“S”型覆岩结构转换和稳定的过程。工作面在“一面采空”条件下,回采过程中发生强矿压的危险性较小|工作面在经历“一面采空”到“两面采空”边界条件转变过程中,其临近已采工作面采空区侧及其端头煤发生强矿压的危险性较上一阶段明显增加|在“两面采空”条件下,本工作面高位岩层与相邻采空区上覆未回转下沉的高位岩梁容易产生连动,形成高位、跨度大的岩梁失稳,使得30202工作面回风巷侧在叠加应力影响下容易发生强矿压。研究结果可为工作面在不同开采条件下采场矿压特征分析、顶板控制和巷道支护设计提供一定借鉴。

Study on spatial structure change of overlying rock in working face under different boundary conditions and its influence on strong mining pressure

In the process of deep mining, with the advance of the working face under different mining conditions, the working face will experience different goaf boundary conditions. Based on the theory of overlying rock spatial structure, the overlying rock structure is called "O" type and "S" type under the condition of “one side goaf” and “two sides goaf” boundary condition, and the overlying rock structure is defined as "O-S" type in the process of their transformation. In order to study the spatial structure change of different overlying rocks in working face and its influence on rock burst, based on theoretical calculation, microseismic monitoring and on-line stress monitoring, the different overlying rock structure types formed during mining in 30202 working face of Muduchaideng Coal Mine are analyzed, and the characteristics of mine pressure appearance and the distribution of rock burst risk area under different overburden spatial structures are analyzed. The results show that under the condition of "one side goaf", the risk of impact in the mining process is small, in the process of changing the boundary conditions from "one side goaf" to "two sides goaf", the impact risk of the goaf side and its end coal in the adjacent working face is obviously higher than that in the previous stage, under the condition of “two sides goaf”, the distribution area of the influence range of inclined supporting pressure on the side of return air roadway is the risk area of rock burst. The research results can be used for reference for the analysis of stope pressure characteristics, roof control and roadway support design under different mining conditions.