基于覆岩结构理论的冲击煤层孤岛工作面宽度研究

Study on the Width of Isolated Coal Face with Rock-burst Hazards Based on the Theory of Overburden Structure

针对冲击煤层孤岛工作面上覆岩结构复杂、开采极易诱发冲击地压等灾害问题,提出了采前孤岛工作面宽度设计的留设方法。以山东某矿为工程背景,首先根据孤岛工作面周边采动情况及覆岩运动规律,确定关键层是否破断,进而得到了孤岛工作面"Γ"型覆岩结构分布;其次采用矿压理论分析不同覆岩结构分布对工作面应力传递规律,估算了孤岛工作面静态支承压力;最后根据孤岛工作面应力分布特点,理论分析了工作面整体支承强度,并结合工作面回采冲击失稳发生机理,确定了工作面宽度合理范围。通过工程类比与理论计算,得到了该矿3上1105孤岛工作面宽度大于170 m的结论,为工作面宽度设计提供理论依据。

According to the problems of complex structure overlying strata in the coal seam isolated coal face which is easy to cause rock burst during mining,a method of designing the width of the face before isolated face working was presented.Taking a mine in Shandong as the engineering background,firstly,according to the working conditions of the isolated island working face and the law of overlying strata movement to judge whether key layer breaking,the isolated working face of ＂ Γ＂ type spatial structure of overlying strata was obtained; Secondly,the stress transfer law of the working face was analyzed by using the theory of mine pressure to estimate the static bearing pressure of isolated working surface; Finally,the overall support strength of the working surface was analyzed according to the stress distribution characteristics of the isolated working face.Combined with the instability mechanism of mining impact in working face,the proper range of the working face width was determined. By engineering analogy and theoretical calculation,the conclusion is that the width of the 3上1105 isolated face working face was more than170 m,which provides a theoretical basis for the design of the working face width.