低温环境下重塑性煤体抗压性能研究

    Study on compressive performance of remoding coal under low temperature environment

    • 摘要: 为研究低温重塑性煤体抗压性能,实现安全快速石门揭煤,防治煤与瓦斯突出,将煤样进行破碎、筛选、压制得到重塑煤样试件,在一定温度(−40、−30、−20、−10、0、20 ℃),一定含水率(0%、4%、8%、12%、16%)相互耦合下进行单轴压缩实验研究,分析重塑性煤体的破坏特征和力学性能。实验结果表明:重塑性煤体在常温(20 ℃)和0 ℃条件下,抗压强度随含水率升高逐渐降低;在冻结温度下,煤样试件内部产生的冻胀力随着温度的降低而逐渐减小,重塑性煤抗压强度得到明显的增强;低温(−40 ℃)和高含水率(16%)耦合作用下重塑性煤体抗压强度、峰值应力、峰值应变均达到最大,最大依次提高164.24%、165.71%、685.72%。

       

      Abstract: In order to study the compressive properties of low-temperature remolded coal, realize safely and rapidly uncovering coal seam in crosscut, and prevent coal and gas outburst, the coal samples were crumbled, selected and suppressed to obtain the remolded coal specimens. The uniaxial compression experiment was carried out under the coupling of a certain moisture content ( 0%, 4%, 8%, 12%, 16% ) and a certain temperature (−40 ℃, −30 ℃, −20 ℃, −10 ℃, −0 ℃, 20 ℃) to analyze the failure characteristics and mechanical properties of remolded coal. The experiment results indicate that: at normal temperature (20 ℃) and 0 ℃, the compressive strength decreases increasingly with the increase of water content. Under the freezing temperature, the frost heaving force inside the coal sample gradually decreases with the decrease of temperature, and the compressive strength of remolded coal is obviously enhanced. Under the coupling effect of low temperature (−40 °C) and high water content (16%), the compressive strength, peak stress and peak strain of the remoulding coal body reached the maximum, which were increased by 164.24%, 165.71% and 685.72% respectively.

       

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