逆断层区域采动煤体力学特征

Mechanical characteristics of mining coal in reverse fault area

为研究逆断层影响区域煤体在采动路径下的力学特征,以新春煤矿1503回采工作面为研究对象,建立逆断层区域采动煤体应力分析模型,计算得出随着工作面与逆断层距离减小,工作面前方采动煤体应力集中程度逐渐增加的变化特征,并采用KBJ-60Ⅲ-1型回采支架工作阻力连续记录仪记录工作阻力,验证了理论计算的结果;基于采动煤体应力变化规律开展煤体力学特征试验,设计3种应力加载方案模拟与逆断层不同距离采动煤体的应力变化,得出煤体力学特征与距逆断层的距离有关,距离逆断层越近,煤体偏应力峰值和应变相对越大,与距离逆断层5m的M1煤样相比,距离逆断层65 m的M3煤样偏应力峰值和轴向应变分别上升了40.74%和26.73%;通过能量分析方法得出与逆断层不同距离的采动煤体裂隙发育特征不同,距离逆断层越近,采动煤体内部存储的弹性相对最高,也消耗更多的能量用于煤体破坏和裂隙扩展。

In order to study the mechanical characteristics of the coal body in the area affected by the reverse fault under the mining path,taking 1503 working face of a mine as the research object,the stress analysis model of the coal body in the area affected by the reverse fault was established,and the change characteristics of the stress concentration degree of the coal body in front of the working face gradually increased with the decrease of the distance between the working face and the reverse fault were calculated,KBJ-60Ⅲ-1 working resistance continuous recorder is used to record the working resistance,which verifies the theoretical calculation results.Then,based on the stress change law of mining coal,the mechanical characteristics test of coal is carried out,and three stress loading schemes are designed to simulate the stress change of mining coal at different distances from the reverse fault.It is concluded that the mechanical characteristic of coal is related to the distance from the reverse fault.The closer the distance from the reverse fault is,the greater the peak value and strain of deviatoric stress of coal is.Compared with M1 coal sample 5 m away from the reverse fault,the peak deviatoric stress and axial strain of M3 coal sample 65 m away from the reverse fault increased by 40.74% and 26.73% respectively.Through energy analysis method,it is concluded that the fracture development characteristics of the mining coal body at different distances from the reverse fault are different.The closer the distance from the reverse fault is,the higher the elasticity of the internal storage of the mining coal body is,and more energy is consumed for coal failure and fracture expansion.