摘要
为探究和预测含瓦斯水合物煤体三轴压缩作用下试样内部的破坏及失稳特征,首先基于瓦斯水合固化方法进行含瓦斯水合物煤体室内三轴压缩试验;同时根据扫描电镜(SEM)图像构建组合Clump颗粒模板,利用颗粒流离散单元法(DEM)模拟方法建立不同颗粒形状(不规则、圆形)、饱和度(40%、60%、80%)的双轴压缩模型,并开展三轴压缩试验;然后从宏观和细观2个方面对比分析Clump颗粒与圆形颗粒对含瓦斯水合物煤体力学性质的影响特征。研究表明:不同颗粒形状含瓦斯水合物煤体试样峰值强度随水合物饱和度的增大均提高,在高饱和度条件下峰值强度增长不明显;不规则颗粒试样强度均大于圆形颗粒试样,最高提升142.01%;饱和度和颗粒形状对试样破坏模式影响较小,不同颗粒形状试样均发生鼓胀破坏且剪切带均呈X型分布;圆形颗粒试样发生旋转颗粒数目明显多于不规则试样,发生破坏的范围更大;随着加载进行,不规则颗粒间能够稳定地分担外部荷载;且不规则颗粒模型平均配位数远大于圆形颗粒试样;在表征含瓦斯水合物煤体力学行为方面,不规则颗粒模型更具优越性。
In order to investigate and predict the internal failure and instability characteristics of gas hydrate coal samples under triaxial action,laboratory triaxial compression tests were first conducted based on the gas hydrate solidification method.Using scanning electron microscope(SEM)images as reference,composite Clump particle templates were constructed to establish biaxial compression models through discrete element method(DEM).The models were featured different particle shapes(irregular and spherical)and saturation levels(40%,60%,80%),followed by simulated triaxial compression tests.A comparative analysis was then performed from both macroscopic and mesoscopic perspectives to examine the effects of Clump particles versus spherical particles on the mechanical behavior of gas hydrate-bearing coal.The results demonstrate that the peak strength of specimens increases with hydrate saturation for both particle shapes.The enhancement becomes less pronounced at higher saturation levels.Irregular particle specimens exhibit significantly greater strength than spherical ones,with maximum strength improvement reaching 142.01%.Both saturation and particle shape show limited influence on failure modes.All specimens exhibit bulging failure and X-shaped shear band distribution.Spherical particle specimens display substantially more particle rotations and larger failure zones compared to irregular particles.During loading,irregular particles form stable load-bearing networks through interlocking,supported by their notably higher average coordination number than spherical particles.These findings confirm the superior performance of irregular particle models in characterizing the mechanical behavior of gas hydrate-bearing coal.
作者
高霞
赵宇贤
王柏琨
吴强
崔祥龙
GAO Xia;ZHAO Yuxian;WANG Baikun;WU Qiang;CUI Xianglong(School of Architectural Engineering,Heilongjiang University of Science&Technology,Harbin Heilongjiang 150022,China;School of Safety Engineering,Heilongjiang University of Science&Technology,Harbin Heilongjiang 150022,China;Zhejiang Zhongke Itasca Rock Engineering R&D Co.,Ltd.,Hangzhou Zhejiang 310051,China)
出处
《中国安全科学学报》
北大核心
2025年第5期106-115,共10页
China Safety Science Journal
基金
国家自然基金联合基金资助(U21A20111)
国家自然科学基金面上项目资助(51974112)。
关键词
颗粒形状
含瓦斯水合物煤体
力学性质
三轴压缩试验
柔性边界
particle shape
gas hydrate-bearing coal
mechanical property
triaxial compression test
flexible boundary
作者简介
高霞(1984-),女,山西忻州人,博士,副教授,主要从事煤岩力学方面的研究。E-mail:klgaoxia1984@163.com;吴强,教授。
