深部工作面采动应力场分布变化规律实测研究

Distribution and variation of mining-induced stress field in deep workface

为防止深部较软煤层发生动力灾害,以平煤股份二矿为工程背景,采用应力实时监测系统测试了深部工作面采动应力场,研究了工作面走向和倾向应力分布及变化规律,分析了应力对煤体稳定性及动力现象的影响,并探讨了工作面可能发生的动力灾害。结果表明,工作面上部(靠近采空区)超前采动影响距离、煤帮内应力集中范围、应力集中系数及应力峰值较大,工作面两端应力规律差异较大。应力峰值和应力梯度变化显著影响煤体的稳定性;通过监测工作面应力变化,可对工作面动力现象进行预测预报;工作面可能发生的动力灾害是应力起主导作用的压出灾害。

To prevent the occurrence of dynamic disaster in deep soft coal seam, based on the engi-neering background in No.2 Coal Mine of Pingdingshan Tianan Coal Co. Ltd., the mining-induced stress field in the deep workface was measured by using the stress real-time monitoring system, and the distribution and variation of stress along strike and inclination was studied. In addition, the effect of stress on coal stability and dynamic phenomena was further analyzed, and the dynamic disasters which may occur in this workface were discussed. The results show that in the upper part of workface, which is approaching the gob-side, the influencing distance of advanced mining-induced stress, the stress con-centration range within the roadway coal sidewalls are larger, and the stress concentration factor and peak value of stress are higher. The stress distribution and variation is quite different between the head and end of the workface. Moreover, the variation of peak stress and stress gradient significantly influ-ence the stability of coalmass. Because the main disaster probably occurred at the workface is extrusion disaster controlled by the stress, the dynamic disasters can be fore casted by monitoring the stress changes at the workface.