基于相似模拟试验的断层防水煤柱留设研究

Study on fault waterproof pillar layout based on similarity simulation experiment

为研究煤层回采过程对断层的影响,以龙东煤矿东二采区边界断层F孙断层为原型,通过相似模拟试验,对7号煤层开采过程中的断层带岩体变形破坏特征、煤层底板应力及位移情况进行监测分析。试验结果表明,随着煤层开采的不断推进,断层带会受到采动作用的影响而发生变形甚至开裂现象;近断层处应变发生改变,煤层底板应力变化明显;并随着断层煤柱宽度的减少,断层带两侧岩体开始出现位移差,断层出现活化的趋势。为防止断层活化导水,应避免断层带两侧岩体出现位移差,据此确定了F孙断层防水煤柱的宽度应不少于50m,并通过经验公式计算,验证了相似模拟试验结果的可靠性。本研究成果为确定合理的断层防水煤柱宽度、保证煤矿安全生产提供了有益依据和参考。

In order to study the effect of coal seam mining on the fault mining effect,taking the Fsunfault at the boundary of the East No.2 mining area in Longdong Mine as the prototype,the similarity simulation experiment was constructed to simulate the deformation and failure characteristics of the faulted rock mass and the stress and displacement of the coal seam floor were monitored and analyzed in No.7 coal seam mining process.The measurement results indicated that with the continuous advancement of coal seam mining,the fault zone was affected by the mining action and it had deformed or even cracked.The mining effect of coal seam on the fault caused the change f strain at the near fault,and the stress at the coal seam floor changed significantly.Along with the reduction of the width of fault pillars,the rock masses on both sides of the fault zone began to show a displacement difference,and the faults appeared to be activated.In order to prevent the activation of faults,the displacement difference between the rock masses on both sides of the fault zone should be avoided,and accordingly,the width of the waterproof pillar of the Fsun fault should be not less than 50 m.The reliability of this similarity simulation test result was verified by the method of empirical formula calculation.This research result provided a useful basis and reference for determining the reasonable width of fault waterproof pillar and ensuring the safety production of coal mine.