综放工作面开切眼掘进及其围岩稳定性控制技术

Open-Off Cut Excavation of Fully-Mechanized Top Coal Caving Mining Face and Stability Control Technology of Surrounding Rock

为解决综放工作面开切眼掘进过程中围岩控制难度大的问题,利用FLAC3D软件对开切眼一次掘进(导硐)、二次掘进(扩宽)过程中围岩扰动情况进行数值模拟,对比分析其位移和应力特征。结果表明:一次掘进时巷道变形量不大,但随着二次掘进宽度的增加,巷道变形量不断增大;顶板变形量主要发生在二次掘进期间,且受二次掘进宽度的影响较大,二次掘进宽度越大,顶板变形量越大。据此提出采用"宽导窄扩"的掘进方式,该掘进方式对围岩的扰动破坏程度较低,通过在西沙河煤矿1901综放工作面开切眼进行工业性试验表明,顶底板最大移近量为98 mm,该掘进方式能有效控制开切眼围岩的变形破坏。

In order to solve a high difficult control problem of surrounding rock in an open-off cut driving process of a fully-mechanized top coal caving mining face,the FLAC3D software was applied to a numerical simulation on disturbance conditions of surrounding rock in a primary driving ( pilot gateway) and secondary driving ( reaming) of the open-off cut and the displacement and stress features were com-pared and analyzed.The results showed that the deformation value of the gateway in the primary driving was not high and with the width of the secondary driving increased,the deformation value of the gateway would be continuously increased. The deformation value of the roof would be occurred mainly during the secondary driving period.With a high influence of the secondary driving width,a larger width of the secondary driving would have more deformation of the roof.Therefore,a wide pilot and narrow reaming driving method was provided and the driving method would have a min disturbance and failure to the surrounding rock. An industrial trial was conducted in an open-off cut of No.1901 fully-mechanized top coal caving mining face in Xishahe Mine and the trial showed that the max convergence between the roof and floor was 98 mm and the driving method could effectively control the deformation and failure of the open-off cut surrounding rock.