剪切-渗流作用下煤岩剪断面形态特征试验研究  

Experimental study on shear-seepage for coal-rock shear fracture surface morphological characteristics

作　　者：许江[1,2] 王威[1,2] 刘义鑫[1,2] 彭守建[1,2] 吴善康 瞿佳美 肖智元 XU Jiang;WANG Wei;LIU Yi-xin;PENG Shou-jian;WU Shan-kang;QU Jia-mei;XIAO Zhi-yuan(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqlng 400044,China;State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam,Chongqing Universlty,Chongqing 400044,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室,重庆400044

出　　处：《岩土力学》2018年第12期4313-4324,4334,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51474040,No.51434003);国家科技重大专项(No.2016ZX05044-02)~~

摘　　要：利用自主研发的煤岩剪切-渗流耦合试验装置,开展了不同法向应力作用下煤岩剪切-渗流耦合试验研究,并对剪断面进行立体扫描,分析不同法向应力作用下煤岩剪断面的二维断面特征参数和三维断面特征参数。结果表明:(1)煤岩试件剪切破坏主要是塑性破坏,在恒定气压条件下,法向应力越大,煤岩的峰值剪应力越高,且煤岩的峰值剪应力与法向应力近似呈线性关系;(2)法向应力是煤岩剪断面形态特征的影响因素之一,在恒定气压条件下,其施加的法向应力越大,二维断面特征参数和三维断面特征参数基本都呈减小趋势,也即法向应力越大,煤岩剪断面的起伏度和粗糙度都越小;(3)在煤岩剪切过程中,法向应力能通过影响剪切裂纹的扩展区域进而影响煤岩试件的渗流特性和剪断面的形貌特征。Based on a self-developed shear-seepage coupling testing device for coal-rock,experimental tests were conducted on coal-rock specimens in the process of CO2injection to investigate shear-seepage of coupled properties.Meanwhile,the sheared fracture surfaces from different normal stresses were scanned,and their characteristics were analysed through two-dimensional (2D) and three-dimensional (3D)statistical parameters.The results show that the shear failure of coal-rock specimen is mainly plastic damage under the condition of constant gas pressure.With the increase of normal stress,the peak shear stress of coal-rock increases as well,and the peak shear stress and normal stress of coal-rock approximate a linear relationship.The normal stress is one of the influence factors of sheared fracture surface characteristics.Under the condition of constant gas pressure,when the normal stress increased,2D and 3D statistical parameters generally showed a trend of decrease,in other words,the sheared fracture roughness and prominence of the coal-rock decreased with the increase of normal stress.Through analysis on coal-rock shearing process,the normal stress can affect the shape and seepage characteristics of sheared fracture surface of the specimen by influencing the extension area of the shear crack.

关 键 词：煤岩 气压 法向应力 剪切-渗流 剪断面 

分 类 号：TU454[建筑科学—岩土工程]