含瓦斯突出煤三轴压缩下力学性质试验研究

EXPERIMENTAL STUDY OF MECHANICAL PROPERTIES OF OUTBURST COAL CONTAINING GAS UNDER TRIAXIAL COMPRESSION

以典型煤与瓦斯突出矿井松藻煤电集团打通一矿7#突出煤层制备的型煤试件为研究对象,利用岛津AG-250伺服材料试验机和自行研制的三轴渗透仪,对不同外界应力条件下含瓦斯突出煤的力学特性进行试验研究。结果表明:瓦斯压力固定的情况下,围压对含瓦斯煤的力学特性起到强化和改善的作用。随着围压的增加,突出煤样的三轴抗压强度、弹性模量和峰值应变均呈线性单调增加;围压大小一定情况下,瓦斯压力对含瓦斯煤的力学特性起到弱化的作用。随着瓦斯压力的增加,突出煤样的三轴抗压强度和弹性模量分别呈线性和对函数形式单调递减,而峰值应变则呈线性单调增加;有效应力对含瓦斯突出煤的力学性质具有强化和改善的作用,随着有效应力的增加,含瓦斯突出煤的弹性模量、三轴抗压强度和峰值应变均单调增加。研究成果对采动影响下煤层瓦斯抽放和煤与瓦斯突出防治及预测具有重要意义。

Based on the briquette specimens of the outburst coal #7 seam of typical coal and gas outburst mine-Datong-One mine of Songzao coal and electricity Co., Ltd., the experiment for studying the mechanical properties of the gas-outburst coal under different external stresses pressure are carried out by a self-developed triaxial permeameter and Daojing AG - 250 rock mechanics servo-controlled testing machine in the paper. The experimental results show that the confining pressure has an enhancement and progress effect on the mechanical properties of outburst coal containing gas under fixed gas pressure, and the triaxial compressive strength, elastic modulus and peak strain are all monotone and linear increasing with the increasing of confining pressure. The gas pressure has a weak effect on the mechanical properties of outburst coal containing gas under fixed confining pressure, the triaxial compressive strength and elastic modulus are respectively linear and logarithm function monotone decreasing with the increasing of gas pressure, but the peak strain is monotone and linear increasing with the increasing of gas pressure. The effective-stress has an enhancement and progress effect on the mechanical properties of outburst coal containing gas, the triaxial compressive strength, elastic modulus and peak strain are all monotone and linear increasing the with the increasing of effective-stress. The experimental results are of significance in gas extraction and the prediction and estimation of coal and gas outburst with the influence of coal mining.