千米埋深坚硬顶板沿空留巷技术研究
Study on technology of gob-side entry retaining with hard roof in 1 000 m deep mine
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摘要: 为解决深井高地应力和坚硬顶板长悬臂高附加应力叠加造成的沿空留巷维护困难的问题,以平煤十二矿己14-31010工作面为研究对象,分析制定了沿空留巷充填墙体构筑工艺流程,提出了以控制坚硬顶板结构为目的的预裂爆破主动卸压技术和沿空留巷围岩强化控制技术方案。对沿空留巷充填墙体构筑与维护过程控制效果监测结果表明:预裂爆破后采煤工作面顶板来压步距缩小10 m左右,工作面液压支架载荷下降约7 MPa,来压强度明显下降;通过巷内强化控制,沿空留巷稳定后巷道断面收缩率为34%,断面面积在10 m~2以上,保证了工作面正常通风和邻近层卸压瓦斯抽采的空间要求,深井高地应力坚硬顶板条件下进行沿空留巷得到成功应用。Abstract: In order to solve a maintenance difficult problem of the gob-side entry retaining caused by the high geostress of the deep mine shaft and the high additio nal stress superposition of the hard roof long suspended boom, based on the Ji 14-31010 coal mining face in Pingmei No. 12 Mine as a study object, a backfill wall con struction technique process of the gob-side entry retaining was analyzed and set up. An active pressure releasing technology with a pre-splitting blasting and a surroun ding rock enhanced control technical plan of the gateway retained along goaf were provided to control the hard roof structure as a target. The control effect monitoring and measuring results of the backfill wall construction and maintenance process for the gob-side entry retaining showed that after the pre-splitting blasting, the roof wei ghting step distance of the coal mining face was reduced about 10 m, the support load of the powered support applied in the coal mining face was reduced about 7 MPa and the roof weighting intensity was obviously reduced. With the enhanced control of the gateway, after the gob-side entry retaining stabillized, the cross section conver gence of the gateway was 34% and the cross section area was over 10m2. Thus the normal ventilation of the coal mining face and the pressure releasing and gas drain age space requirement could be ensured and the gob-side entry retaining was successfully applied under the condition of the high geostress and hard rood in the deep mine shaft.
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