深部高瓦斯煤层冲击地压发生机理研究

Mechanism Research on Rock Burst in Deep Coal Seam with High Gas

针对深部高瓦斯煤层的冲击地压灾害,从瓦斯对煤体强度影响、瓦斯煤体在卸载下的层裂现象及瓦斯煤体积聚静态能量3方面入手,探讨瓦斯煤层冲击地压的发生机理。通过理论推导得出:瓦斯降低了煤体强度,减小了煤体破坏时所需要的能量;含瓦斯煤体突然卸载后,受地应力和瓦斯共同作用会产生层裂现象,削弱了冲击显现区煤体抵抗变形的能力;最终在集中动载荷和耦合静态能量的共同作用下,建立了瓦斯煤层发生冲击地压的能量判据,指出了瓦斯煤体更容易发生冲击地压。此外,在冲击地压发生后往往出现瓦斯异常涌出的现象,瓦斯积聚对安全生产带来隐患,甚至引起煤与瓦斯突出等动力灾害。

For rock burst disasters in deep high gassy coal seam,we discuss occurrence mechanism of gassy seam rock burst from the influence of gas on coal body strength,the crack phenomenon of gas coal in unloading condition and gas and coal accumulation static energy. Through theoretical deduction,firstly gas reduces the strength of coal and reduces the energy that coal destruction required;besides,coal seam containing gas suddenly unloaded,spall fracture is caused by the joint action of ground stress and gas,which weakens ability of resisting deformation of coal; under the combined action of concentrated dynamic load and static energy,the energy criterion of rock burst in gassy seam is established. It is pointed out that coal containing gas is more prone to the rock burst. Besides,it often appears the phenomenon of abnormal gas outburst after the rock burst; gas accumulation brings hidden trouble to safety production,even,causes coal and gas outburst and other dynamic disasters.