煤矿直接顶与老顶离层破坏影响因素分析

复合巷道支护是国内外巷道支护的难题之一，而复合巷道在我国煤矿巷道中有着广泛的分布．煤巷的开挖位置一旦确定，其围岩结构状态就不再改变，岩层结构上的薄弱部位即为巷道的关键部位．巷道顶板离层破坏影响因素很多，通过对煤层直接顶、老顶的厚度以及岩体的强度等分析，确定其对顶板离层的影响程度，并结合力学分析，建立顶板离层力学模型，计算出顶板离层深度，另外还利用FLAC3D模拟软件，模拟复合巷道在不同环境下老顶与直接顶的变形量，从而得出引起顶板离层破坏的影响因素．

Analysis on the factors affecting the old roof and the direct roof separation in coal mine

The supporting of the compound wall rock roadway is one of the difficult problems in supporting the compound roadways , which are distributed widely in the coal mine tunnel of our country. The state of the rock structure cannot be changed when the excava- tion location is determined, and the weak part of the rock becomes the key part of the roadway. Laneway roof separation failure is influ- enced by many factors such as the coal seam roof, the original roof thickness and the strength of the rock mass . The effect of such fac- tors on the degree of the roof separation was ascertained. The mechanical modal of roof separation was built, combined with the me- chanical analysis, and the depth of the roof separation was calculated. In addition, the composite roof deformation of the original roof and seam roof in different environment were simulated by using FLAC3D software, thus the factors causing the damage of roof separa- tion were obtained .