超长综采工作面矿压显现规律研究

Study on Underground Pressure Manifestation Law of Ultra-long Fully-mechanized Working Face

为掌握超长综采工作面矿压显现规律及发生机理,采用理论分析、数值模拟和现场观测的研究方法,对河南某矿300 m超长综采工作面矿压显现规律及发生机理进行分析。结果表明:随着工作面长度增加,采空区应力由“中间大、两端小”的上凸半圆弧形分布逐渐演化为“两端大、中间小”的马鞍形分布;10-103综采工作面基本顶初次来压步距和周期来压步距分别为23.88 m和9.75 m;工作面长度为250 m和300 m时顶板垂直应力和塑性区分布特征基本相似,但应力峰值位置由工作面前方5 m处增加至前方6 m,应力集中系数由1.57增大至1.58。现场观测表明:上部支架工作阻力多接近或超过上限,工作面出现老顶来压;下部支架工作阻力基本维持在上、下限之间,工作面来压较缓和;中部支架工作状态良好,无明显周期来压。

In order to grasp the law and occurrence mechanism of the underground pressure of the ultra-long fully-mechanized working face,the research methods of theoretical analysis,numerical simulation and on-site observation were used to analyze the underground pressure manifestation law and occurrence mechanism of the 300 m ultra-long fully-mechanized working face of a mine in Henan.The results show that with the increase of the working face length,the goaf stress gradually evolves from the convex semi-circular arc distribution of"large in the middle and small at both ends"to the saddle-shaped distribution of"large at both ends and small in the middle".The 10-103 fully-mechanized working face basic top first pressure step distance and periodic pressure step distance are23.88 m and 9.75 m,respectively;when the working face length is 250 m and 300 m,the distribution characteristics of the vertical stress and plastic zone of the top plate are basically similar,but the peak stress position is increased from 5 m in front of the work to 6 m in front,and the stress concentration coefficient is increased from 1.57 to 1.58.On-site observation shows that the working resistance of the upper bracket is close to or exceeds the upper limit,and the working face appears to be pressed by the old top;the working resistance of the lower bracket is basically maintained between the upper and lower limits,and the working face is more relaxed;the central bracket works well with no significant cycles to press.