水软化作用下页岩微观结构和力学性质演化特性  

Evolution Characteristics of Shale Rock Microstructure and Mechanical Properties under the Action of Water Softening

作　　者：罗攀登[1] 赵兵[1] 冯禹菲 张妹珠 LUO Pandeng;ZHAO Bing;FENG Yufei;ZHANG Meizhu(Research Institute of Petroleum Engineering Technology,Sinopec Northwest Oilfield Company,Urumqi 830011,China;School of Civil and Architectural Engineering,Wuhan University,Wuhan 430072,China;Office of Scientific Research and Development,Wuhan University,Wuhan 430072,China)

机构地区：[1]中国石化西北油田分公司石油工程技术研究院,新疆乌鲁木齐830011 [2]武汉大学土木建筑工程学院,湖北武汉430072 [3]武汉大学科学技术发展研究院,湖北武汉430072

出　　处：《金属矿山》2024年第8期29-34,共6页Metal Mine

基　　金：中国石化科技攻关项目(编号:P20064-3)。

摘　　要：在雨水或者地下水的浸泡下,页岩力学性质会大幅度降低,容易导致泥石流、隧洞塌陷、滑坡等灾害。以页岩为研究对象,通过微观岩石力学试验研究了水软化作用下页岩的微观结构和力学特性演变规律。研究结果表明:在浸水10 d后,页岩表面粗糙度平均值和最大值分别增至259.1 nm和561.9 nm。页岩主要由石英、绿泥石、伊利石和钠长石组成,其中绿泥石为层状硅酸盐。在水软化作用下绿泥石发生崩解并且释放晶层间膨胀力,导致页岩样品粗糙度增加。随着浸水时间的增加,高、中、低3类强度矿物的弹性模量逐渐减小;低强度矿物的黏聚力呈现下降趋势,从16.7 MPa降低到6.0 MPa,而内摩擦角随浸泡时间轻微波动,其平均值为42.5°。The mechanical properties of shale will be greatly reduced under the immersion of rainwater or groundwater,which can easily lead to disasters such as mudslides,tunnel collapse,and landslides.Taking the shale as the research object,the microstructure and mechanical properties evolution of shale under the action of water softening were studied through microscopic rock mechanics experiments.The results show that the average and maximum surface roughness of shale increase to 259.1 nm and 561.9 nm respectively after 10 days of immersion.The shale is mainly composed of quartz,chlorite,illite and albite,in which chlorite is layered silicate.Under the action of water softening,chlorite disintegrates and releases the expansion force between crystal layers,resulting in an increase in the roughness of shale samples.With the increase of soaking time,the elastic modulus of high,medium and low strength minerals decreases gradually.The cohesion of low-strength minerals decreased from 16.7 MPa to 6.0 MPa,while the internal friction angle fluctuated slightly with the soaking time,with an average value of 42.5°.

关 键 词：页岩 水软化 微观岩石力学试验 纳米压痕试验 

分 类 号：TD315[矿业工程—矿井建设]