静、动载荷下含弱层煤岩间超低摩擦效应

Ultra-low friction effect of weakly layered composite rock coal under static and dynamic loads

针对深部开采中发生冲击地压后大部分煤岩体向巷道整体倾出,在顶板表面出现摩擦痕迹的问题,利用数值模拟方法对静、动载荷作用下含弱层组合煤岩体的动力响应进行研究分析。结果表明:不同加载方式下煤块表现出不同的动力响应,通过对比可知,水平方向扰动是发生超低摩擦效应的主要原因,垂直方向的扰动则会加速超低摩擦的发生;水平残余位移随着水平静力的增大而增强,且在1200~1300 N时发生突变;在静、动载荷同时作用下并施加不同特征区间的水平力,煤块的运动状态随之改变,说明弱层的存在对于应力波具有消减的作用。此外,水平残余位移随着冲击载荷的增大呈对数增加,且在100~200 N时发生突变。

During some coal bursts in deep mining,coal was ejected into the roadway along the coal-roof contact,leaving gouges in the roof surface.The dynamic response of a coal with a weak layer under static and dynamic load is studied and analyzed using numerical simulation.The results show that the coal shows different dynamic responses under different loading conditions.Horizontal disturbance is the main cause of ultra-low friction effect,while vertical disturbance accelerates the occurrence of ultra-low friction.The horizontal residual displacement increases with the horizontal force,and there is a sudden change between 1200 N and 1300 N.Under the simultaneous action of static and dynamic loads and the application of horizontal forces in different characteristic intervals,the movement state of coal changes accordingly,indicating that the existence of weak layer can reduce the stress wave.In addition,the horizontal residual displacement increases logarithmically with the magnitude of impact load and abruptly changes between 100 N and 200 N.