广西河池红层泥岩力学特性的纳米压痕试验研究  

Nanoindentation experimental study on mechanical properties of red mudstone in Hechi,Guangxi Province

作　　者：罗婷倚 张清淞 刘志彬[2] 唐亚森 王宇婷 LUO Tingyi;ZHANG Qingsong;LIU Zhibin;TANG Yasen;WANG Yuting(Guangxi Beitou Highway Construction and Investment Group Co.,Ltd.,Nanning 530029,China;Institute of Geotechnical Engineering,School of Transportation,Southeast University,Nanjing 210096,China)

机构地区：[1]广西北投公路建设投资集团有限公司,广西南宁530029 [2]东南大学交通学院岩土工程研究所,江苏南京210096

出　　处：《水资源与水工程学报》2022年第6期174-181,共8页Journal of Water Resources and Water Engineering

基　　金：国家自然科学基金项目(41877240)。

摘　　要：为了系统表征广西河池地区红层泥岩中各矿物组分的力学性质,采用纳米压痕测试技术,测试了红层泥岩样品在4种峰值荷载下的力学性能,并结合X射线衍射仪和光学显微镜等设备,将每个测点结果依次对应到各矿物组分上。结果表明:广西河池地区红层泥岩内部具有高度的非均质性,主要成分以SiO_(2)、Al_(2)O_(3)、Fe_(2)O_(3)为主,所含矿物组分主要包括石英、斜长石、白云母等。黏土矿物和各种矿物组分呈紧密、无规律排列。单次纳米压痕试验的泥岩荷载-压入深度曲线的离散化程度较高,但每组荷载下的12个测点的平均最大压入深度和塑性变形满足荷载越大则压痕深度越大的基本规律。当峰值荷载较小时,泥岩中各测点的弹性模量和硬度体现了良好的线性相关性。泥岩中的石英成分强度最高,力学性能最好,斜长石次之;白云母和黏土矿物的力学性能最差。同时,红层泥岩内部表现为多孔隙、多裂缝结构,导致黏土矿物的平均弹性模量低于其他类岩石的水平,这也是导致红层泥岩易开裂、遇水易崩解的原因。In order to systematically characterize the mechanical properties of each mineral component in the red mudstone in Hechi area,Guangxi Province,the nanoindentation technology is used to study the mechanical properties of red mudstone samples under four peak loads.According to the test resuts of a X-ray diffractometer,an optical microscope and other instruments,the measurement of each test point are linked with each mineral component correspondingly.The results show that the red mudstone in Hechi area of Guangxi Province has high heterogeneity,it is mainly composed of SiO_(2),Al_(2)O_(3) and Fe_(2)O_(3),with quartz,plagioclase,muscovite,etc.as the main mineral components.The clay minerals and other mineral components are closely and irregularly arranged.The mudstone load-indentation depth curve of single nanoindentation test has a high degree of discretization,but the average maximum indentation depth and plastic deformation of 12 measuring points under each group of load present the same pattern,which is the greater the load,the greater the indentation depth.When the load is relatively small,the elastic modulus of each measuring point is in a good linear correlation with the hardness.The quartz in the mudstone has the highest strength and the best mechanical properties,followed by plagioclase;whereas muscovite and clay minerals have the worst mechanical properties.Because the red mudstone is characterized by porous and fractured structure,the average elastic modulus of its clay minerals is lower than that in other types of rocks,which is also the reason why the red mudstone is prone to fractures and easy to disintegrate in contact of water.

关 键 词：红层泥岩 纳米压痕 矿物组分 峰值荷载 微观力学特性 

分 类 号：TU454[建筑科学—岩土工程] TV16[建筑科学—土工工程]