抽采负压对煤体单轴抗压强度影响规律的实验研究

Experimental investigation on the effect of pumping negative pressure on uniaxial compression strength of coal body

为研究抽采负压对煤体单轴抗压强度的影响,构建了负压环境煤体力学实验系统,开展了不同抽采负压下煤体单轴压缩力学实验。实验采用的抽采负压分别为70kPa、45kPa、30kPa与13kPa,并设置了常压及含瓦斯环境(200kPa、500kPa、1000kPa)作为对比。结果表明,负压环境下煤体强度明显大于常压及含瓦斯环境下的强度,抽采负压对煤体具有强化作用;煤体的峰值应变在常压变为13kPa、13kPa变为30kPa、30kPa变为45kPa、45kPa变为70kPa时分别增大了11.6%、4.74%、7.560%、10.78%,而弹性模量则分别增加了3.27%、2.03%、2.86%、6.53%。实验结果表明随着抽采负压的增大,煤体的单轴抗压强度、峰值应变和弹性模量均呈现增大的趋势,上述研究成果对瓦斯抽采的理论研究具有参考意义。

In order to investigate the effect of pumping negative pressure on uniaxial compression strength of coal body, UTM4204 electronic universal testing machine was used to measure the uniaxial compression strength of coal body in different pumping negative pressure environments. The negative pressure of extraction is selected as 70kPa, 45kPa, 30kPa and 13kPa, respectively, and the atmospheric pressure and 200kPa, 500kPa and 1000kPa gas pressure are set respectively as comparison between gas pressure and environmental pressure. Results show that the strength of coal body in negative pressure environment is obviously higher than that in normal pressure and atmosphere with gas condition, and the existence of negative pressure in extraction will strengthen At the same time, the gas pressure increases from normal pressure to 13kPa, 13kPa to 30kPa, 30kPa to 45kPa, 45kPa to 70kPa, the peak strain and elastic modulus of the coal increased by 11.6%, 3.27%;4.74%, 2.03;7.560%, 2.86%;10.78%, 6.53%, respectively. Experimental results show that the coal body strength, peak strain and elastic modulus increase with the increase of suction negative pressure.