瓦斯吸附作用下煤体爆破裂隙扩展规律研究

Study on Law of Cracks Propagation in Coal Blasting Under Gas Adsorption

为了探究不同瓦斯压力作用下煤体爆破裂隙扩展规律,基于含瓦斯煤体力学性质异于普通煤体的研究成果,利用LS-DYNA有限元软件,在普通煤体物理力学参数的基础上进行强度修正以确定含瓦斯煤体力学参数,对不同瓦斯压力作用下的煤体爆破裂隙扩展进行模拟,并对应力场在普通及含瓦斯煤中传播、衰减规律进行分析。结果表明:煤体粉碎区、裂隙区半径随瓦斯压力增大而增大,裂隙分布更加密集;在爆破近区,含瓦斯煤体单元峰值压力随瓦斯压力增大略微降低,在爆破中远区,单元峰值压力升高,且含瓦斯煤体中应力场衰减速度低于普通煤体,应力作用时间增长,促使煤体破碎。

To explore the rules of the expansion of blasting cracks in coal under different gas pressures,based on the research results that the mechanical properties of gas-containing coal are different from those of ordinary coal,the strength modification is carried out on the basis of the physical and mechanical parameters of ordinary coal to determine the mechanical parameters of gas-containing coal.LS-DYNA finite element software is used to simulate the expansion of coal blasting cracks under different gas pressures,and the propagation and attenuation law of stress field in ordinary and gas-containing coal are analyzed.The results show that the radius of coal crushing zone and fracture zone increases with the increase of gas pressure,and the distribution of fracture is denser.In the near area of blasting,the peak pressure of gas-containing coal unit decreases slightly with the increase of gas pressure;in the far area of blasting,the peak pressure of unit increases,and the attenuation rate of stress field in gas-containing coal is lower than that of ordinary coal,and the stress action time increases,which causes the coal to break.