煤与瓦斯突出发展过程的实验与机理分析

为了研究煤与瓦斯突出发展过程中煤的破坏形式和原因，通过实验分析了含瓦斯煤块在突然暴露时的破坏规律，用简单的突出模型进行了各种条件下的突出发展模拟实验，并建立了突出发展的数学模型。结果表明，突出发展过程中煤的破坏主要表现为层裂形式，破坏传播的速度非常快（大于1 m/ms），在突出发展初期不存在剧烈的粉化破坏。突出发展过程中煤中裂隙初始起裂主要是由于煤壁突然卸载形成的卸载波向里传播过程中被受围岩约束的煤部分反射回去，入射波和反射波叠加使煤处于受拉状态而发生拉伸破坏。即便地应力为零，含瓦斯煤体在突然形成暴露面时也会产生向深部传播的卸载波，进而引发层裂。

Experiment and mechanism analysis of the developing process of coal and gas outburst

In order to study the form and reason of coal damage during the developing process of coal and gas outburst,some experiments were performed to study the breakage characteristic of suddenly exposed gassy coal,simulations of the outburst developing process were also performed in various conditions with a simplified outburst model,and a mathematical model for coal and gas development was built.The results show that the main form of coal damage is spall fracture,the speed of damage propagation is very fast(greater than 1 m/ms),and there is no violent pulverization damage in the initial stage of outburst development.An unloading wave will occur after the sudden unload of coal wall,and it may be reflected by the restrained coal when propagating into coal body,the incoming wave and reflecting wave interact to produce a tension area and thus lead to tensile failure of coal,which is the reason of fracture initiation during the developing process of outburst.Even if there is no ground stress,sudden exposedness of a coal wall may also induce unloading wave that propagates into deep area,and thus induces spall fracture of coal.