7.0m支架综采面矿压显现规律研究

Strata Behavior of Fully-Mechanized Face with 7.0 m Height Support

基于神东矿区补连塔煤矿22303工作面矿压实测结果,对世界首个7.0 m支架综采面不同开采阶段的矿压显现规律进行了总结,并结合神东矿区各类大采高综采面的矿压显现,对比分析了不同采高综采面矿压显现规律的差异。结果表明:上覆遗留煤柱区下开采时7.0 m支架工作面矿压显现正常,但在临近推出煤柱区时,工作面内煤壁片帮现象严重,直接导致刮板板输送机被压死。而长壁采空区下开采时,7.0 m支架工作面在煤层间单一关键层结构和2层关键层结构区域呈现出不同的矿压显现。煤层间单一关键层结构区域,关键层距离煤层越近,矿压显现各项参数(除来压步距外)越大;而在煤层间2层关键层结构区域,工作面来压步距及动载系数呈现出大小交替的周期性变化规律,且大来压步距对应小动载系数。通过对比7.0 m支架综采面与神东矿区其它几个大采高综采面的矿压显现规律发现,随着采高的增加,支架支护强度缓慢增加,而动载系数随之减小,且采高越大、亚关键层1距离煤层越近,越易形成亚关键层1的"悬臂梁"结构,从而来压持续长度越长。

Based on the measured results of ground pressure in No.22303 working face of Bulianta Coal Mine,Shendong mining area,the strata behaviors in different stages of the first 7.0m height fully-mechanized face around the world are summarized in this paper,and combining with the strata behaviors in various fully-mechanized faces of Shendong mining area,the differences of various fully-mechanized faces are comparatively analyzed in detail.The results show that the strata behavior of 7.0 m support fully-mechanized face remains regular when mining under the overlying coal pillars,but when nearly mining out of the pillar area,the coal wall caves,largely which directly leads to the crush-ing death of the scraper conveyor.While mining under the long wall goaf,the strata behavior of single key stratum structure in 7.0 m fully-mechanized face differs from that in double key strata structure.Within the single key stratum structure,the nearer the key stratum structure to the coal seam is,the lar-ger the parameters of strata behavior are（except the roof weighting step）,while within the double key strata structure,the roof weighting step and dynamic load coefficient present periodical alternating changes,and the large roof weighting step comes along with the small dynamic load coefficient.Through comparing the strata behaviors between 7.0 m fully-mechanized face and several other fully-mechanized faces in Shendong mining area,we conclude that the higher the mining height is,the larger the support strength is,and the smaller the dynamic load coefficient is.In addition,the higher the mining height is,and the nearer the first inferior key strata to the coal seam is,it is more easier to form ＂cantilever＂ structure in the first inferior key strata,so as to lengthen the roof weighting.