首页|水-瓦斯耦合作用下煤岩抗压特性劣化试验研究

水-瓦斯耦合作用下煤岩抗压特性劣化试验研究

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闭坑高瓦斯矿井中煤岩体在水和瓦斯的劣化作用下力学特性劣化,这将直接影响其稳定性和安全性。为研究水-瓦斯耦合作用下煤岩抗压特性,基于水-岩-气耦合试验系统,开展了浸泡环境下的全水浸(EW)、半水浸半气浸(WG)及全气浸(EG)煤样和干燥(CZ)煤样的单轴压缩试验,分析了煤样抗压强度及变形破坏特征,并从煤样浸泡前后的组分、宏观结构及破裂断口细观特征的角度,揭示了水-瓦斯耦合作用下煤岩的宏观、细观劣化机制。结果表明,在三种浸泡条件下,煤样抗压强度较干燥煤样均降低,EG组、WG组和EW组煤样抗压强度分别降低了18。92%、38。31%和53。45%,三种浸泡条件下煤样破坏模式由干燥煤样的剪切破坏转变为剪切-拉伸混合式破坏,破坏程度也随之增大,煤样由脆性破坏转变为塑性破坏,导致浸泡后煤样局部化带范围和错动程度增大;煤样在三种浸泡环境中劣化效果主要表现为:1)水和瓦斯的侵入导致煤样内部黏土矿物分解和析出,与CZ组相比,EG组、WG组和EW组煤样平均黏土矿物含量分别降低了3。8%、28。85%和45。94%,煤样孔隙结构发生改变;2)各组煤样浸泡后表面出现劣化效应,EG组表面孔隙发育程度劣于EW组,且EW组煤样表面出现剥落现象,WG组煤样水浸部分孔隙发育程度要胜于气浸部分;3)水和瓦斯的劣化作用使煤样内部孔隙结构发生改变,EW组、WG组和EG组煤样破裂断口平均孔隙率较CZ组分别增加了706。84%、362。95%、147。47%。在三种浸泡环境下煤样初始承载结构被破坏,降低了煤样破坏前储存能量的能力,破坏后煤样内部的剩余弹性能降低,耗散能增加,声发射累计振铃计数降低。上述研究对于认识闭坑高瓦斯矿井中煤岩体的稳定性具有一定的参考意义。
Deterioration of compressive properties of coal rocks under water and gas coupling
The compressive properties of coal under water-gas coupling were studied based on the water-rock-gas coupling test system.The compressive strength and deformation damage characteristics of the coal samples were analyzed,and the macro and fine degradation mechanisms of coal under water-gas coupling were revealed.The compressive strength of the coal samples under the three soaking conditions was reduced compared to that of the dry coal samples.The damage mode of coal samples changed from tensile damage of dry coal samples to mixed shear-tensile damage.Coal samples changed from brittle damage to plastic damage,which increased the range of localization zones and the misalignment of coal samples after soaking.The deterioration effects of coal samples in the three soaking environments were mainly as follows:1)The intrusion of water and gas led to the decomposition and precipitation of clay minerals inside coal samples;2)The surface of each group of coal samples showed a deterioration effect after soaking;3)The deterioration effect of water and gas changed the internal pore structure of coal samples.The destruction of the original supporting structure of the coal samples in the soaked environment reduced the ability of the coal samples to store energy before destruction.

water-gas couplingabandoned minescompressive characteristicsdeterioration characteristics

吕科、江宁、尹大伟、孟书宇、高志友、吕涛

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College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China

General Institute of Exploration and Research of China National Administration of Coal Geology,Beijing 100039,China

Shandong Geology and Mineral Resources Engineering Group Co.,Ltd.,Jinan 250013,China

水-瓦斯耦合 废弃矿井 抗压特性 劣化特性

国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金中国博士后科学基金

U23A206005237412752274128521741592022M713386

2024

中南大学学报(英文版)
中南大学

中南大学学报(英文版)

CSTPCDEI
影响因子:0.47
ISSN:2095-2899
年,卷(期):2024.31(2)
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