基于高精度微地震监测技术,并结合岩石力学理论进行分析,得到滕东生建煤矿3107工作面回采过程中覆岩运动规律,对千米深井厚煤层开采条件下小采宽综放工作面支架围岩关系进行了研究。结果表明,微震事件在低位岩层高密度分布,在高位岩层低密度分布;微震事件在空间和时间上的周期性分布规律与顶板岩层的周期运动过程相一致,高位岩层的断裂强迫低位岩层断裂;工作面支架围岩关系随着基本顶的周期性断裂运动存在2种情况:1)基本顶非周期来压期间,支架压力来源于厚度4.4m的顶煤、厚度20m的下位直接硕和部分厚度15m的上位直接顶共同产生的静压;2)基本顶周期来压期间,支架压力来源于基本顶断裂产生的动压以及顶煤和直接顶产生的静压。动压对支架产生冲击载荷,这是工作面支架被压死的主要原因,通过提前减小顶煤放出率、减小支架控顶距等措施,可减弱动压对支架的冲击影响。
Based on the high precision microseismic monitoring technology and the rock mechanics and rock pressure theory, overburden strata movement law has been gained at 3107 working face in Shengjian Coal Mine, and the relationship between support and surrounding rock on the fully mechanized top coal caving face in thick coal seam of kilometer deep mine has been studied. The results show that the microseismic events located within the lower strata are of high density distribution, and microseismic events located within the higher strata are of low density distribution. The periodic distribution of microseismic events in both space and time correspond to the periodic movement of roof strata, and the high rock fracatre force the lower strata fracture. The relationship between support and strata high rock fracture force the lower strata fracture. The relationship between support and strata with periodic rock fracture of the basic roof can be drawn as follows: 1) In the aperiodic weighting period, the basic load of the support originates in the static pressure caused by such forces as the top coal of 4.4 meters thickness, the lower immediate roof of 20 meters thickness and part of the upper immediate roof of 20 meters thickness; 2) In the periodic weighting period, the basic load of the support originates in the dynamic pressure caused by the basic roof fracture and the static pressure caused by the weight of the top coal and the immediate roof. The dynamic pressure causes impact load on the support, which is the main reason that hydraulic support is crushed. rate in advance and increase of support extension Some measures such as decrease of top coal recovery should be taken so as to reduce the impact on the hydraulic support.