Research on structural plane separation threshold and stability of compound roof in coal mining

摘要

In order to judge the separation stability of the structural plane of the compound roof in coal mining, the separation threshold should be reasonably determined. In this paper the stress of structural plane and the distribution of interlayers separation under different in-situ stress were simulated and analyzed by 5x5 orthogonal experiments which are considering five factors including the roadway width, the rock properties of the compound roof, the thickness of the compound roof, the cohesion and the internal frication angle of the structural plane with ANSYS. Based on these experiments, the criterion of the structural plane separation threshold was put forward and the structural plane separation threshold under different conditions was obtained. The test results show that the threshold is only significantly related to the width of the roadway. The thickness of the compound roof has a significant effect on the stability of the structural plane and also the rock properties of the compound roof have a strong influence, whereas the mechanic properties of the compound roof have a small effect. Although the width of the roadway has a significant influence on the separation threshold range of the structural plane, it has no obvious effect on the separation stability.