温度对采动作用下含瓦斯原煤力学和变形的影响

Influence of Temperature on the Mechanical and Deformation Properties of Containing-Gas Raw Coal Under Mining

以原煤为研究对象,利用"含瓦斯煤热流固耦合三轴伺服渗流实验装置",开展温度对采动作用下含瓦斯煤力学特性的影响研究.研究表明:1)在相同初始围压、气压和温度下,与恒定围压相比,卸围压煤样屈服段缩短,峰值应力和对应的轴向应变降低,横向应变速率增大,侧向膨胀系数和变形模量的演化进程加速;2)在相同初始围压和气压下,随温度升高,卸围压煤样强度降低,峰值应力处各应变均减小,侧向膨胀系数和变形模量均增大;3)高温环境下,煤岩发生失稳破坏和瓦斯突出的危险性变大,对采煤工作面巷道支护和瓦斯突出防治提出了更高的要求.

Taking raw coal as object,by using self-made “ thermal- hydro-mechanical coupled with triaxial servo-controlled seepage apparatus for containing-gas coal”,the effect of temperature on the mechanical properties of containing-gas raw coal was studied under constant confining pressure and unloading confining pressure. The results showed that： 1） Under the same initial confining pressure,gas pressure and temperature,compared with the constant confining pressure, the yield stage of the coal under unloading confining pressure is shortened. Besides,its peak stress and associated axial strain decrease, the transverse strain rate increases, and the evolution processes of its lateral expansion ratio and deformation modulus are accelerated. 2） Under the same initial confining pressure and gas pressure,with the increase of temperature,the strength of coal under unloading confining pressure decreases,the axial strain at peak stress,the absolute value of the transverse strain and volumetric strain decrease,and the lateral expansion ratio and the deformation modulus increase. 3 ） The risk of coal unstable failure and coal and gas outburst becomes higher under high temperature environment,leading to more strict requirements for the support of coal face roadway and the control of coal and gas outburst.