不同围压下含瓦斯气体及水合物煤体的力学性质

Study on mechanical properties of gas and hydrate bearing coal under different confining pressures

为研究围压对含瓦斯气体及水合物煤体的力学影响,取龙煤集团桃山矿务局井下600 m突出煤层的型煤,利用水合固化反应与三轴压缩一体化实验装置,对含瓦斯气体及水合物型煤进行常规三轴压缩实验,研究不同围压下两种煤样的力学性质。结果表明:随着围压增加,两种煤样的应力-应变关系有从软化型向硬化型转化趋势,水合物的生成加大了这种趋势,提升了煤样的黏聚力,对内摩擦角影响不大;瓦斯压力不变时,突出煤体试样的抗压强度、峰值强度和变形模量都随着围压的增加呈线性增加的关系;随围压增大煤样破坏面从径向偏向轴向,破裂角逐渐变大。

This paper is devoted to investigating the mechanical properties of gas and hydrate bearing coal under different confining pressures. The investigation draws on a series of conventional triaxial com- pression experiments on the gas and hydrate bearing coal obtained from -600 m outburst coal seam in Taoshan coal mine of Heilongjiang Longmay Mining Holdings Refeo Group Ltd using the self-developed integrated apparatus for gashydrate formation and triaxial compression. The results show that an increase in confining pressure results in a tendency of converting from softening type to sclerotic type in the stress- strain curves of two kinds of coal samples, and the formation of hydrate not only strengthens this trend, but also enhances the cohesion of the coal samples, but without any effect on the internal friction angles; the constant gas pressure provides a linear increase in the compressive strength, the peak strength and de- formation modulus of the outburst coal samples due to an increase in confining pressures; and an increase in confining pressures tends to change the failure surface of coal samples from radial direction to an axial one, contributing to a gradually larger rupture angle.