深厚松散层薄基岩条件下覆岩破坏高度实测分析

Site Measurement and Analysis on Failure Height of Overburden Strata Under Thick Loose Alluvium and Thin Bedrock

赵固一矿首采面上覆松散层厚大于518 m,基岩厚小于80 m,为获得开采后覆岩垮落带和导水裂缝带的高度,合理确定工作面开采上限,采用地面钻孔观测法对该首采面覆岩的破坏高度进行了观测,并对钻孔设计、钻孔施工和"两带"高度判别方法进行了研究分析。观测结果表明:该首采面垮落带发育高度为13.1 m,垮采比为3.85,导水裂缝带发育高度大于29.2 m,裂采比大于8.59,该结果与相似模拟试验值和数值模拟值基本吻合,相互得到验证。

The thickness of the overburden strata above the first coal mining face in Zhaogu No.1 Mine was over 518 m and the thickness of the bedrock was less than 80 m.In order to have the height of the overburden strata falling zone and water conducted crack zone after coal mining operation completed and to rationally set up the top limit for the mining operation of the coal mining face,the surface borehole observation method was applied to observe the failure height of the overburden strata before and after the coal mining operation of the coal mining face.A study and analysis was conducted on the borehole design,borehole drilling operations and height distinguishing method of the two zones.The observation results showed that the development height of the falling zone in the first coal mining face was 13.1 m,the falling and mining ratio was 3.85,the development height of the water conductive crack zone was higher than 29.2 m and the crack and mining ratio was larger than 8.59.The results could be basically meet the similar simulation test value and the numerical simulation value and could be mutually confirmed.