含瓦斯煤失稳破坏及渗流特征试验与模拟研究

Experiment and Simulation Study on Failure and Seepage Characteristics of Gas-bearing Coal

为了探究工作面推进速度与煤岩动力灾害的内在联系,采用理论、试验和模拟相结合的方法进行了加速加卸载条件下含瓦斯煤失稳破坏及渗流特征的试验与模拟研究。试验结果表明,在加速加载路径下,试样的应力集中程度更高,失稳后渗透率激增的幅度更大;在加速卸载路径下,试样更易发生破坏,破坏后渗透率的增幅更大。在理论上建立了考虑加卸载速度变化的含瓦斯煤流固耦合模型。基于构建的模型,以试验方案为例,采用COMSOL软件模拟了4个路径的力学特性变化与瓦斯渗流过程,并将模拟结果与试验结果进行对比。结果表明:试验曲线和模拟曲线整体变化趋势、变化区间基本相同,验证了模型的适用性。研究成果对于煤岩动力灾害防治、丰富矿井瓦斯防治理论具有重要意义。

In order to explore the inherent relationship between the acceleration of working face and the dynamic disasters of coal and rock,a combination method of theory,experiment and simulation was used to conduct the study on the failure and seepage characteristics of gas-bearing coal under accelerated loading and unloading conditions.The experimental results show that under the accelerated loading path,the stress concentration of the sample is higher,and the amplitude of the permeability surge is larger after instability.Under the accelerated unloading path,the sample is more likely to be damaged,and the increase of the permeability is greater after failure.A fluid-solid coupling model for gas-bearing coal considering the change of loading and unloading rate was theoretically established.Based on the coupling model,taking the experimental scheme as an example,COMSOL software was used to simulate the mechanical and seepage processes under the four paths.Then,the simulation results were compared with the experimental results.The comparison results show that the overall trend and interval of the experimental curve and the simulated curve are basically the same,which verifies the applicability of the model.The research results are of great significance for the prevention of coal and rock dynamic disasters and enriching the theory of gas prevention in mine.