近距离煤层群叠加开采采动应力与覆岩位移场演化特征

为获得近距离煤层群叠加开采条件下采动应力与覆岩位移场的演化特征，以潘二矿近距离煤层6，7煤层地质条件为背景，采用相似模拟与工程实践相结合的方法进行了研究。结果表明:近距离煤层群叠加开采形成的覆岩宏观运移形态和特征与单一煤层开采相似，叠加开采时，覆岩呈多岩层整体协调运移的规律，具有位移叠加增长效应；7煤层的开采使覆岩起到一定的垫层作用，缓和了矿山压力，使近距离煤层叠加开采时具有应力减弱效应；与开采7煤层相比，6煤层开采过程中，周期来压步距减小，来压时支架载荷减弱，动压系数相应减小，但周期来压时，存在部分岩层发生台阶式下沉的现象。基于近距离煤层群叠加开采研究结果，在近距离煤层群开采的设备选型时，选用了高额定工作阻力的液压支架，在周期来压期间，采取了一定的辅助措施，同时加强了组织管理，生产中没有发生冲击液压支架及其他动力灾害的现象。

Evolution characteristics of mining stress and overlying strata displacement field under superimposed mining in close distance coal seam group

In order to obtain the evolution characteristics of mining stress and overlying strata displacement field under the superimposed mining in close distance coal seam group, the study was carried out by using the combined methods of similar simulation and engineering practice based on the background of geological conditions at No. 6 and 7 coal seams in Pan'er coal mine. The results showed that the macro migration form and characteristics of overlying strata produced by the superimposed mining in close distance coal seams were similar to that of single coal seam, and the overlying strata under superimposed mining presented the law of overall coordination migration for multiple strata, with a displacement superposition growth effect. The overlying strata played a certain cushion effect due to the mining of No.7 coal seam, which mitigated the mine pressure, and caused the stress weakening effect under the superimposed mining in close distance coal seam group. The periodic weighting interval reduced, the support load when weighting weakened, and the dynamic pressure coefficient reduced accordingly in the mining process of No.6 coal seam compared with No.7 coal seam, but there was a phenomenon that the stepped sinking occurred in partial strata during the periodic weighting. The hydraulic supports with high rated working resistance were selected in the equipment type selection based on the results of superimposed mining in close distance coal seam group. Because of taking a certain auxiliary measures and strengthening the organization and management at the same time during the periodic weighting, there were no phenomena of impacting the hydraulic supports and other dynamic disasters in the production.