断层影响区工作面埋深对煤柱稳定性影响研究

Research on the influence of work face depth on coal pillar stability in fault-affected zone

基于杨柳矿实际的工程地质数据,通过数值模拟软件FLAC3D建立断层模型,模拟了工作面不同埋深地质条件,得到了不同开采深度下工作面与断层间不同宽度煤柱垂直应力演化特征及垂直应力集中系数演化规律。模拟研究数据表明,煤柱承载的垂直应力及应力集中系数并不是随埋深显现线性增加或减小变化;煤柱垂直应力在工作面浅埋深开采时呈直线型线性增大,中等及深埋深呈阶梯型逐渐缓慢上升,速度较浅埋深工作面慢;煤柱垂直应力集中系数在浅埋深工作面开采时呈线性快速上升,应力集中系数较中等及深埋深大,但埋深小,故应力集中数值偏小,工作面采动是发生冲击地压的主要影响因素;在中等及深埋深工作面应力集中系数逐阶减小,但是应力集中数值较大,主要是上覆岩层较厚影响,埋深是工作面发生冲击地压的主要影响因素,且受埋深影响工作面易发生冲击地压。

The fault model was built by numerical simulation software FLAC3D to simulate the different buried-depth geological conditions of work face in Yangliu Mine.The evolutionary characteristics of the vertical support stress and the vertical stress concentration factor evolution law for different width coal pillars between the work face and the fault were obtained under different depths of mining.The simulation study data showed that the bearing stress and the stress concentration factor carried by coal pillars did not increase or decrease linearly with the burial depth.The support stress of coal pillars increased linearly and linearly at the shallow depth of the work face.The ladder type stress gradually increased slowly,and the speed was slower than that of the shallow buried surface.The pillar stress concentration factor of coal pillars raised linearly and rapidly when the shallow depth work face was mined.The stress concentration factor was relatively medium and deep,but the depth was small.The stress concentration value was small,the mining impact at work face was the main influencing factor of rock burst;the stress concentration coefficient in the middle and deep burial work face decreased step by step,but the stress concentration value was larger,mainly impacted by the thicker overlying rock,burial depth was the main influencing factor of rock burst in work face,and it was affected by the depth of the impact surface.