影响巷道顶板稳定的关键块体的受力分析

针对巷道开挖后,围岩体中成因各异、种类不同的弱面将巷道围岩体分割成不同几何形状、不同尺寸的块体,且部分块体暴露在巷道的临空面上,由于相互摩擦及挤压形成不稳定平衡。其中某关键块体的受力、结构形状以及裂隙弱面的强度性质决定该巷道顶板的变形及稳定性。针对该关键块体可能的组合运动趋势(滑动、倾倒),用矢量分析理论给予受力分析,给出了巷道稳定平衡的条件,为完善巷道支护提供了理论依据,并在实践中得到应用。

The Mechanics Analysis of the Key Block Affecting Roadways′ Roof Stability

Roadways unsteadiness of underground rock-mass affected by completely cut cranny has ubiquitous features.After drived,roadway around-rock was divided as blocks of all kind of shapes and different dimensions by all kind of joint plane.Because of inter-friction and pressure,part of blocks being exposed in roadway surface should form unsteadiness equilibrium,and key-block loads,the black shapes and cranny's strength decide roof deformation and its stability.With vector analysis theory,the possible moving trend(sliding,dumpage) of "key block" was discussed,and then roadways roof stability conditions are put forward.The research outcomes provide theory foundation for roadways supporting design,and were succussesfully applied in practice.