深埋隧道炭质板岩微观结构及单轴压缩试验研究  

An experimental study of microstructure and uniaxial compression test of carbonaceous slate in a deep buried tunnel

作　　者：谢云鹏 陈秋南[1] 黄小城[1,2] 罗鹏 XIE Yunpeng;CHEN Qiunan;HUANG Xiaocheng;LUO Peng(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;School of Civil Engineering,Chongqing University,Chongqing 400044,China;Hunan Sunshine Construction Co.Ltd.,Changsha,Hunan 410022,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康监测湖南省重点实验室,湖南湘潭411201 [2]重庆大学土木学院,重庆400044 [3]湖南尚上建设开发有限公司,湖南长沙410022

出　　处：《水文地质工程地质》2020年第1期96-102,共7页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金(41172275;41372303);湖南省交通厅科技进步与创新项目资助(201229;201712)

摘　　要：炭质板岩隧道施工过程中受高地应力、地下水冲刷和施工扰动等因素影响,从细观角度分析其微裂隙变化规律具有重要意义。在实际工程现场选取炭质板岩试样,采用扫描电子显微镜(SEM)进行背散射分析,确定其组成元素;进行X射线衍射仪分析,利用MDI Jade 6软件处理,得到矿物成分及其含量;通过不同含水条件下炭质板岩单轴压缩实验得到不同含水量下的应力应变曲线、各阶段的变形特征及破坏规律。结果表明:炭质板岩中主要有石英、白云母及钠长石,其组成物质完全解理易形成贯穿裂隙;炭质板岩达到最大峰值强度前近于弹性变形。随浸水时间增长,炭质板岩应力应变曲线四阶段逐渐明显,且峰值后应力跌落减缓。主要力学特性表现为:矿物间结构由于水的润滑作用,水楔作用及潜蚀作用遭到破坏。岩石弹性模量、单轴抗压强度显著降低,泊松比、峰值应变略有增大,宏观表现为裂隙角度变缓。High in-situ stress,groundwater erosion and construction disturbance may affect the construction of tunnels in carbonaceous slate rocks. It is of great significance to analyze the relationship of microfissures from the view of meso-view. The carbonaceous slate samples were selected in the actual engineering site,and the backscattering analysis was carried out by scanning electron microscope( SEM) to determine the components of the samples. The X-ray diffractometer was used to analyze the mineral compositions and their contents were obtained by using the MDI Jade-6 software. The stress-strain curves of carbonaceous slate under different water contents were obtained by the uniaxial compression test under different water-cut conditions, and the deformation characteristics and failure law of each stage were obtained. The results show that there are mainly quartz,muscovite and albite in the carbonaceous slate, and the extremely complete cleavage of the carbonaceous slate is easy to form penetrating fissures,and the maximum strength of the carbonaceous slate is close to the elastic deformation before it reaches the peak strength. With the increasing immersion time,the stress-strain curve of the slate gradually becomes obvious in four stages,and the stress drop slows down after the peak value. The main mechanical characteristics are as follows: the intermineral structure is destroyed by water lubrication,water wedge action and latent corrosion. The elastic modulus and the uniaxial compressive strength of rock decrease significantly, and the Poisson’s ratio and peak strain increase slightly.Macroscopically,the angle of fissures changes slowly.

关 键 词：深埋炭质板岩 矿物组成 微观结构 破坏特性 单轴力学试验 

分 类 号：P642.3[天文地球—工程地质学] TU45[天文地球—地质矿产勘探]