组合煤岩结构体冲击倾向演化数值模拟

Numerical simulation experiments on bursting liability evolution of compound coal-rock structure

针对单纯以煤层或顶板岩层进行煤层冲击倾向性判定存在"低估"问题,采用RFPA2D模拟软件开展不同高度比和不同顶板强度、厚度、均质性及接触面角度下组合煤岩结构体的冲击倾向性数值试验.研究结果表明:组合煤岩结构体冲击倾向性高于纯煤层或岩层测定结果,更接近实际.随着顶板强度、厚度、均质性的增加,组合煤岩结构体冲击倾向性增强,随接触面角度的增大,其单轴抗压强度降低,峰后塑性变形阶段越来越明显.在接触面角度一定的情况下,随着顶板岩体强度的增加,组合煤岩结构体冲击破坏声发射累计释放能量减弱.

Bursting liability as an index for coal rock burst dangerous evaluation, is sometimes under/over estimated for the stability of coal and rock. The numerical experiments of different heighet ratio and different roof strength, homogeneity, and interface angle to the structure bursting liability were researched based on coal-rock compound structure samples with RFPA2D software. The results of study show that the bursting liability of coal-rock compound structure higher than single coal or single rock, which is closer to actual value. With the increasing of the strength, the height and the heterogeneity index of rock, the bursting liability of coal-rock compound structure becomes stronger. When the rock burst tendency index increases, the combined body whole strength decreases with the interface angle increasing, and the post-peak plastic deformations is more obvious.With a certan interface angle, the accumulative AE energy decreases as the roof strength increases. In addition,when the bursting liability is stronger, the accumulative AE energy of coal-rock compound structure is weaker during the phase of plastic deformation.