煤体瓦斯吸附与放散过程中的应力分析

摘要

为研究煤体在吸附和放散瓦斯过程中的力学特征,使用煤层瓦斯动力作用模拟系统试验平台,建立了煤体瓦斯吸附与放散物理试验模型,对煤体在瓦斯吸附和放散过程的煤体总应力、瓦斯压力和瓦斯放散速度等参数进行了监测。模拟试验结果表明：对于刚性围岩中的煤体,当煤体瓦斯从游离态向吸附态转化过程中,煤体总应力略微降低,孔隙压力和有效应力随时间分别按照对数规律减小和增大;煤体瓦斯向煤体外放散阶段,瓦斯压力和煤体总应力随时间按照负指数规律降低,有效应力随时间略有降低,瓦斯放散速度随时间按照对数规律降低。此研究成果可对矿井瓦斯动力灾%In order to study the mechanics features of coal during the gas adsorption and emission process,a experiment platform of the coal gas dynamical effect simulation system was applied to establish a coal gas adsorption and emission physical experiment model.A monitoring and measurement was conducted on the coal total stress,gas pressure,gas emission velocity and other parameters of coal during the gas adsorption and emission process.The simulation experiment results showed that as for the coal in the rigid surrounding rocks,when the coal gas converted from a free state to an adsorption state,the coal total stress would be slightly low and the void pressure and the effective stress would be reduced and increased with the time and individually according to the logarithmic law.During the coal gas emission period,the gas pressure and the coal total stress would be reduced with the time and according to the negative index law,the effective stress would be slightly reduced with the time and the gas emission velocity would be reduced with the time and according to the logarithmic law.The study achievements would have certain reference values to the prevention and control of the mine gas dynamic disaster and to the theoretical study on the coal bed methane development technology.