滕县煤田太原组薄煤层开采覆岩破坏高度及规律研究

Research on the Height and Law of Overlying Rock Failure During the Mining of Thin Coal Seams in Taiyuan Formation of Tengxian Coalfield

滕县煤田下组煤为典型的深埋薄煤层,导水裂隙带发育规律不明显,高度难以预测。为研究滕县煤田导水裂隙带发育情况及覆岩破坏规律,以滨湖煤矿21603工作面为研究对象,采用理论公式与3DEC数值模拟的方法,对采掘扰动后的覆岩破裂高度及规律开展研究,并采用“双端封堵侧漏”实测法进行了验证。3DEC数值模拟通过分析覆岩裂隙发育特征、塑性区变形特征、顶底板应力分布特征以及位移监测,多方位确定采掘扰动对导水裂隙带发育高度的影响。研究结果表明:滨湖煤矿21603工作面覆岩导水裂隙带实测高度为22.98 m,3DEC模拟结果相较于传统经验公式准确率较高,达91.92%,3DEC模拟的多方位分析方法对滨湖煤矿以及滕县煤田开采扰动下导水裂隙带发育高度的预测具有指导意义。

The lower formation coal seam in Tengxian Coalfield is a typical deep buried thin coal seam,and the development law of water conducting fracture zones is not obvious,making it difficult to predict the height.In order to study the development situation of water conducting fracture zones and the law of overlying rock failure in Tengxian Coalfield,taking the 21603 working face of Binhu Coal Mine as the research object.Theoretical formulas and 3DEC numerical simulation methods are used to study the fracture height and law of overlying rock after mining and excavation disturbance,and the"double end sealing side leakage"measurement method is used for verification.3DEC numerical simulation determines the influence of mining and excavation disturbance on the development height of water conducting fracture zones from multiple perspectives by analyzing the characteristics of fissures development,plastic zone deformation,roof and floor stress distribution and displacement monitoring.The research results indicate that the measured height of the overlying water conducting fracture zone in the 21603 working face of Binhu Coal Mine is 22.98 m.Compared with traditional empirical formulas,the accuracy rate of 3DEC simulation results is higher,reaching 91.92%.The multi-directional analysis method of 3DEC simulation has guiding significance for predicting the development height of water conducting fracture zones under mining disturbance in Binhu Coal Mine and Tengxian Coalfield.