破碎煤岩峰后渗流-蠕变实验

Experimental study on creep-seepage peak after crushing coal

为探究煤岩体峰前峰后的渗流蠕变规律,设计了基于自主研发三轴渗流蠕变测试仪的渗流蠕变实验.通过采用控制变量法分别递增围压、轴压、孔压,拟合曲线得出了随着围压、轴压、孔压的分别递增情况下的煤岩体峰前及峰后渗流蠕变规律.实验结果表明:煤岩体未破碎之前,渗流量与孔压成正比、与围压成反比,且随着裂隙的增多,渗流量也会逐渐增大;煤岩体蠕变速率随着轴压的增大而增大;峰后煤岩的裂隙会在轴压和水流作用下先扩张后压密,轴向变形和横向变形的速率急速增长,轴压随着松弛不断降低后趋于平缓,渗流量随着裂隙的变化先增大后减少,围压在横向变形作用下不断上升.

In order to explore the seepage - creep law front and after the peak of coal （rock）, this paper designed an experiment based on an independent researching triaxial seepage - creep tester. By using the control variable law to respectively increase the axial pressure, the lateral pressure and the pore pressure by degrees, this study performed curve fitting and obtained the seepage - creep law front and after the peak of coal（rock） in the case of respectively increasing the axial pressure, the lateral pressure and the pore pressure by degrees. The experimental results show that, before coal and rock is not broken, seepage discharge is proportional to pore pressure and is inversely proportional to the lateral pressure, and with the increase in cracks, seepage discharge will gradually increase; creep rate of coal（rock） increases as the axial pressure increases; after the peak, the cracks of coal （rock） will be expanded first and then be compacted by the action of water and axial pressure, axial deformation and lateral deformation rate will growth rapidly; with the relaxation, axial pressure will constantly reduce and tend gentle at last; with the change in cracks, seepage discharge increases first and then reduces; lateral pressure constant rises in the action of lateral deformation.