逆断层不同倾角对采场冲击地压的诱导分析

Coal bump inducing rule by dip angles of thrust fault

归纳了易造成冲击地压发生的主控参量,分析了断层倾角对冲击效应的力学机理,建立了逆断层简化模型,研究了不同断层倾角条件下的应力场、能量场、顶板下沉量等诱冲因素对冲击地压的基本作用规律。研究表明:上盘开采时,断层倾角小于45°的工作面超前支承压力峰值、弹性能峰值及顶板下沉量随断层倾角的增大而增大,大于45°时随断层倾角的增大而减小;下盘开采时,工作面超前支承压力峰值随断层倾角的增大而减小,且断层倾角为60°及75°时,工作面超前支承压力峰值前移,增加了冲击危险性;断层倾角大于45°的工作面前方弹性能峰值及顶板下沉量随断层倾角的增大而减小,小于45°的随断层倾角的增大而增大。无论上盘或下盘开采,断层区域弹性能及垂直应力都随着断层倾角的增加而增加。总体而言,断层倾角对下盘开采影响比上盘大。

In this paper, the main control parameters for coal bumps were generalized, and the mechanical mechanism of coal bump induced by fault dip. In addition, the simplified model of thrust fault was constructed, and the effect law of stress field, energy field and roof subsidence, etc., that inducing coal bump was simulated and studied in the conditions of different fault dip angles. The results show that when mining in the hanging wall, the peak abutment pressure, peak elastic energy and roof subsidence increase with the increase of fault dip in the condition of fault dip smaller than 45°, and while the fault dip is greater than 45°, the opposite results will be obtained. When mining in the footwall, the peak abutment pressure in front of the face decreases with the increase of fault angle. While the fault dip is 60° or 75°, the peak abutment pressure moves forward, which will raise the coal bump risk. The peak elastic energy and roof subsidence ahead of the face decrease with the increase of fault dip in the condition of fault dip smaller than 45°, and while the fault dip is greater than 45°, the opposite results will be obtained. Whether mining in hanging wall or footwall, the elastic energy and vertical stress in the fault area will increase with the increase of fault dip angle. In a word, fault dip angle has a greater influence to coal face when mining in the footwall.