含气体突出煤岩纵波波速与应力耦合关系研究

为了更好地将震动波CT技术运用于煤与瓦斯突出灾害监测中,搭建了含气体突出煤岩三轴压缩波速测试系统,实验室研究了含气体煤岩所受轴压、围压和所通入的气压大小与波速之间的耦合关系,并建立了波速与各应力的数学模型。研究表明:当试样载荷不变时,随着通入气压的增大,纵波波速在开始会剧烈下降,随后趋于稳定,呈线性负相关;当围压和气压条件不变时,试样在开始受到轴压后,波速迅速增大,随后波速变化趋于平缓,接近线性增长,呈指数函数关系;当气压和围压条件不变时,试样的纵波波速会随着围压的增加而均匀增加,呈线性正相关;3种试验结果所拟合出来的数学模型均具有较高的相关性。

Study on coupling relationship between longitudinal wave velocity and stress of coal outburst with gas

In order to give an accurate warning of coal and gas outburst disaster, a triaxial compression wave velocity test system of coal and rock with gas outburst was built. The coupling relationship between the axial pressure, confining pressure, the gas pressure and wave velocity of coal and rock with gas was studied under the laboratory conditions, and the mathematical model of wave velocity and pressure was established. The results show that: when the load of the sample is constant, with the increase of the gas pressure, the longitudinal wave velocity will decrease sharply at the beginning, and then tend to be stable, showing a linear negative correlation;when the confining pressure and the air pressure conditions are constant, the wave velocity of the sample will increase rapidly after the axial pressure is applied at the beginning, and then the wave velocity tends to be flat and increases linearly, showing an exponential function relationship;when the air pressure and the confining pressure strip, with the increase of confining pressure, the longitudinal velocity of the specimen increases uniformly and linearly, and the mathematical model fitted by the three test results has a high correlation coefficient.