针对淮南矿区顾北煤矿-648 m水平绞车房硐室底板突出严重,容易发生拉剪破坏的特点,首先采用FLAC3D对绞车房硐室支护前的围岩变形和应力分布特征进行了模拟分析:变截面处和底角应力集中明显,在高应力作用下底角剪切滑移和底板折断隆起是造成底臌的根本原因。基于分步联合支护理论,对绞车房硐室底板支护方案进行了优化,并对绞车房硐室表面与深部位移、锚索受力和基础内部应力进行了全方位监测,结果表明:原支护方案下巷道底板变形较大,巷道底角发生剪切滑移诱使巷道断面圆形化,注浆花管和底角地梁可以较好地抵抗底角处的剪切滑移;巷道底板变形量受地应力方位影响较大,采用新的底板联合支护方式不仅可以很好地满足绞车房硐室对底板变形的要求,还能加强两帮稳定性,同时保证了绞车房基础稳定。
In this paper, the FLAC3 D software is applied firstly to simulate the deformation and stress distribution of the winch room at level of-648 m, considering the serious floor heave and characteristics of tensile-shear damage in Gubei Coal Mine of Huainan. From simulation results, obvious stress concentration is found at variable cross-sections and corners. The results also demonstrate that the fundamental reason of floor heave is caused by base shear slip and floor fracture uplift under high in-situ stress. Based on the theory of stepwise supporting, the supporting method for winch room floor is optimized. Moreover, the surface and deep displacement, anchor cable tensile force and the internal stress of concrete foundation are monitored. From the monitoring results, we can see that roadway floor heave occurs and the cross section of roadway tends to roundness with the original support method; the grouting tube and the base beam can well resist base shear slip; floor deformation is influenced greatly by in-situ stress orientation, and the newly combined supporting method can not only control floor deformation, but also effectively enhance the stabilities of roadway walls and concrete foundation of winch room.