软弱岩层下回采巷道围岩变形及控制技术研究

Study on Surrounding Rock Deformation and Controlling Technique of Mining Roadway Under Soft Rock

长壁开采过程中,由于采场侧向支承应力的影响,常常使得回采巷道严重变形。以察哈素煤矿31305工作面为研究对象,借助FLAC^(3D)软件,分析采场矿压对回采巷道变形的影响;提出顶板定向爆破技术,并对切缝深度以及相配套的恒阻锚索进行了理论分析及实验;采用FLAC^(3D)数值模拟软件对预期的工程效果进行模拟。结果表明,顶板定向爆破极大地降低了回采巷道围岩变形破坏的风险,各巷道顶板下沉量均有明显下降,当31305工作面顶板定向爆破切缝深度为6.8m,采用350 kN恒阻锚索支护后,在超前工作面9m处,其回采巷道顶板下沉最大值为243 mm,有效提高回采巷道的稳定性。

During the process of longwall mining, due to the influence of lateral supporting pressure of stope, which make the deformation phenomenon of mining roadway more serious. Taking 31305 work- ing face of Chahasu Coal Mine as the study example, based on FLAC3D software, the influence of stope mining perssure on the deformtion of mining roadway is analyzed; then, the directional roof blasting technique is proposed, and theoretical analysis and test of slit depth and matched constant resistance an- chor cable are done; finally, the application effects of the above technique are discussed by adopting FLAC3D numerical simulation software. The results show that risk of deformation failure of the surrounding rock of the mining roadway is reduced greatly by using directional roof blasting technique, the subsidence of roadway roof is decreased significantly, when the directional blasting slit depth of the roof of 31305 working face is 6.8 m, the supporting scheme based on 350 kN constant resistance anchor cable is ap- plied, the maximum subsidence of roadway roof is 243 mm in the area that is 9 m ahead of working face, the stability of the stoping roadway is improved effectively.