层间作用对岩层断裂的影响

Effect of the Action Between Rock Layers on their Fracture

运用弹性力学基本理论分析了采场顶板岩层层间作用对岩层应力状态的影响；根据最大拉应力准则，建立了岩层破断位置的确定方法。结果表明，岩层中最大拉应力并非一定发生在最大弯矩所在的截面上，因而岩层也并不一定沿煤壁发生断裂。这一结论很好地解释了采场上覆岩层塌落范围自下而上逐层收敛的现象。

Using the principle of elasticity theory,the effect of the action between rock layers on their stress states are analyzed.Based on the principle of highest tensile stress,the method to judge the fracture porition of rock layer is put forward.The results indicates that the highest tensile stress is not always in the cross section acted by the largest bending force,thus the fracture position is not always parallel with coal wall.The conclusion makes the fact clear that the caving range of the rock layers above the face is shrinking from the lower to the higher.