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通过采用Winkler弹性基础理论、UDEC数值模拟和实验室相似材料模拟方法,研究了邻近岩层约束作用对顶板断裂位置的影响。研究得出:单梁模型由于没有考虑覆岩的约束作用,其分析结果与实际存在较大差别;煤壁塑性区的存在是顶板超前煤壁断裂的前提,但由于受覆岩约束的影响,断裂位置通常并不与弹塑性分界重合,也不与离层起始点重合,其间关系受岩梁刚度、煤层刚度、层间黏结力大小影响;顶板刚度越大,断裂位置越靠近弹塑性分界点,顶板刚度越小则越靠近煤壁;层间黏度越大,断裂位置越靠近煤壁,甚至出现在煤壁后方。
By using Winkler elastic foundation theory, UDEC numerical simulation and laboratory simulation of similar materials, the effect of adjacent strata constraint on roof fracture location was studied. The results show that the single-beam model does not consider the confinement effect of overlying strata, and the analysis results are quite different from the actual ones. The existence of plastic zone in coal wall is the prerequisite for the coal wall fracture ahead of the roof. However, due to the influence of overburden strata constraint, The fracture location usually does not coincide with the elasto-plastic demarcation nor coincides with the starting point of the delamination. The relationship between them is influenced by the rigidity of the rock girder, the stiffness of the coal seam and the size of the cohesion between layers. The greater the stiffness of the roof, the closer the fracture position is to the demarcation point , The smaller the stiffness of the roof is, the closer to the coal wall. The greater the interlayer viscosity, the closer the fracture location is to the coal wall and even behind the coal wall.