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准确预测采场底板破坏深度是承压水上采煤的一个关键问题,而目前常用的解析解公式没有考虑底板水压力的影响。为此,将底板视为各向同性均质弹性体,支撑压力和水压力作为均布条形荷载分别作用在底板上下面,依据弹性半空间理论的符拉芒和明德林解,推导出采场底板的应力表达式。在此基础上,分析了水压力对底板应力分布规律的影响。根据应力计算结果,利用带拉伸破坏的Mohr-Coulomb准则对底板破坏深度进行计算,并探讨了水压力和隔水底板厚度对计算结果的影响。算例显示,水压力对底板垂直应力和剪应力影响较小,而对水平应力影响较大,使其出现应力扩散现象。底板剪切和拉伸破坏深度和范围随水压力的加大而明显增大,随着隔水层厚度的增大只略微降低,表明加大隔水层厚度并不能有效降低底板破坏深度。实例应用表明,水压力影响下的底板破坏深度计算值与实测值基本吻合,较不考虑水压力的计算精度要高。
Accurately forecasting the failure depth of stope floor is a key issue of confined water mining, and the commonly used analytical solution does not consider the influence of floor water pressure. For this reason, the bottom plate is regarded as an isotropic homogeneous elastic body, and the support pressure and the water pressure act as a uniform strip-shaped load on the upper and lower surfaces of the sole plate, respectively. Based on the elastic half-space theory, Stope floor stress expression. On this basis, the influence of water pressure on the stress distribution of floor is analyzed. Based on the results of stress calculation, the failure depth of floor was calculated by Mohr-Coulomb criterion with tensile failure and the influence of water pressure and water-proof floor thickness on the calculation results was discussed. The examples show that water pressure has little effect on the vertical stress and shear stress of the floor, but has a greater impact on the horizontal stress, resulting in the phenomenon of stress diffusion. The depth and range of shear failure and tensile failure of the slab increase obviously with the increase of water pressure and decrease only slightly with the increase of the thickness of the riser. It is concluded that increasing the thickness of the riser can not effectively reduce the depth of failure of the slab. The practical application shows that the calculation value of the failure depth under the influence of water pressure basically agrees with the measured value, and the calculation accuracy of water pressure is higher than that without considering the water pressure.