【摘要】 为揭示吸附性气体对煤的损伤作用机理,利用可视化恒定容积气固耦合试验装置分别开展了CO₂,CH₄,N₂,He 4种气体诱发型煤损伤试验研究,测定了不同吸附性气体作用下型煤单轴抗压强度和破坏形态,并用颗粒流软件PFC进行了数值模拟。主要结论如下:1)不具吸附性的He对煤的单轴抗压强度基本无影响;2)煤体强度损失与气体吸附量呈现一致性,相同吸附平衡压力下,气体吸附性越强,煤的损伤越显著,先后顺序为:CO₂> CH4>N2;3)煤的破坏形态和裂纹扩展规律与气体吸附量相关,CO₂作用下煤体裂纹呈现"裂隙窄、数量多"的特点,He作用下煤体裂纹呈现"裂隙宽、数量少"的特点;4)气体吸附诱导煤颗粒间的接触发生改变,煤粒吸附气体将引发颗粒间的黏结抗拉强度和黏结黏聚力减小,进而引起宏观力学参数变化,造成煤岩损伤和强度损失。更多还原

【Abstract】 In order to reveal the damage mechanism of structural coal by adsorbent gas, the structural coal damage test induced by four gas of CO₂, CH₄, N₂ and He was carried out by visualized constant volume gas-solid coupling test device. The uniaxial compressive strength and failure mode of coal were measured by the test, and then simulated by particle flow software PFC. The main conclusions are as follows: 1) As He isn’t adsorbent gas, it has no effect on the uniaxial compressive strength of coal; 2) The strength loss of coal is consistent with the amount of gas adsorption. Under the same adsorption equilibrium pressure, the degree of coal damage increases in accordance with the gas adsorption amount. The degree of coal damage is: CO₂> CH₄> N2; 3) The failure mode and crack propagation characteristics of coal are also related to the amount of gas adsorption. The coal damage under CO₂ is characterized by "narrow crack with large quantity". However, the coal damage under He shows the characteristics of "wide crack with small quantity"; 4) The gas absorption induces the change of contact between coal particles, and the tensile strength and the cohesive force of the bond between the particles are then reduced by those adsorbed gas, which could cause changes in macroscopic mechanical parameters, resulting in coal and rock damage and strength loss.更多还原