| 昔格达组半成岩微观结构与力学性质研究 |
| |
| 引用本文： | 杜宇翔,盛谦,王帅,付晓东,罗红星,田明,王立纬,梅鸿儒.昔格达组半成岩微观结构与力学性质研究[J].岩土力学,2020,41(4):1247-1258. |
| |
| 作者姓名： | 杜宇翔 盛谦 王帅 付晓东 罗红星 田明 王立纬 梅鸿儒 |
| |
| 作者单位： | 1. 中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室，湖北 武汉 430071；2. 中国科学院大学，北京 100049；
3. 长江科学院 水利部岩土力学与工程重点实验室，湖北 武汉 430010；4. 云南大永高速公路有限公司，云南 大理 671000；
5. 云南省交通投资建设集团有限公司，云南 昆明 650200；6. 沈阳工业大学 建筑与土木工程学院，辽宁 沈阳 110870；
7. 湖北工业大学 土木建筑与环境学院，湖北 武汉 430068 |
| |
| 基金项目： | 云南省交通科技项目《云交科教[2017]33号》；NSFC-云南联合基金重点资助项目（No. U1402231）；国家自然科学基金（No. 51779250）。 |
| |
| 摘 要： | 以金沙江寨子村昔格达组半成岩为研究对象，通过X射线衍射、电镜扫描，测定了矿物成分、天然与饱和状态矿物颗粒微观结构；通过三轴压缩试验，研究了昔格达组半成岩受水和围压影响的强度及变形变化规律，并探讨了微观机制；通过对昔格达组半成岩、土、软岩强度指标与含水率的关系进行统计，分析了昔格达组半成岩不同于土和软岩的强度特性，并给出了针对此类岩土体的工程分级建议。研究表明：（1）微观结构显示昔格达组半成岩有明显不同于土和岩石的弱胶结结构特征，在饱和后胶结结构易遭破坏；（2）昔格达组半成岩黏聚力、摩擦角均随含水率增加而减小，平均模量在高含水率下随围压增加而增大，围压一定时随含水率增加而减小；（3）昔格达组半成岩、土、软岩的黏聚力大小为软岩>昔格达组半成岩>土，黏聚力对含水率的敏感性为软岩>昔格达组半成岩>土，摩擦角对含水率的敏感性为土>昔格达组半成岩>软岩；（4）将Φ50 mm×100 mm标准试件的单轴抗压强度在0.2～3 MPa，黏聚力在30～200 kPa的岩土体归类为硬土?软岩，建议在工程实际应用中将其与岩石和土进行区分。
|
| 关 键 词： | 昔格达 半成岩 含水率 微观结构 强度变形指标 工程分级 |
| 收稿时间： | 2019-04-21 |
| 修稿时间： | 2019-07-07 |
Study of microstructure and mechanical properties of semi-diagenetic
rock of Xigeda Formation |
| |
| DU Yu-xiang,SHENG Qian,WANG Shuai,FU Xiao-dong,LUO Hong-xing,TIAN Ming,WANG Li-wei,MEI Hong-ru.Study of microstructure and mechanical properties of semi-diagenetic
rock of Xigeda Formation[J].Rock and Soil Mechanics,2020,41(4):1247-1258. |
| |
| Authors: | DU Yu-xiang SHENG Qian WANG Shuai FU Xiao-dong LUO Hong-xing TIAN Ming WANG Li-wei MEI Hong-ru |
| |
| Abstract: | In this study, semi-diagenetic rock specimens of the Xigeda Formation in Zhaizi village on Jinshajiang River were investigated. The mineral composition of the specimens was determined by X-ray diffraction (XRD), and the microstructure and change of mineral particles in natural and saturated states were observed by scanning electron microscopy (SEM). The influences of water and confining pressure on the strength and deformation of semi-diagenetic rock of Xigeda Formation were determined using triaxial compression test. And the microcosmic mechanism was also discussed. The strength characteristics of the semi-diagenetic rocks of Xigeda Formation different from that of the soil and the soft rock were revealed by statistical analysis of the relationship between the strength indexes and water content of rock, soil and soft rock. On the basis, engineering classification suggestions for the semi-diagenetic rocks of Xigeda Formation were given. Based on the above research, some conclusions are as follows. 1) The microstructure shows that the semi-diagenetic rock of Xigeda formation has weak cementitious structure which is obviously different from that of soil and rock. The cementation structure is easy to be destroyed after saturation. 2) The cohesion and friction angle of semi-diagenetic rock decrease with the increase of water content. The average modulus increases with the increase of confining pressure at high water content, it decreases with the increase of moisture content when the confining pressure is constant. 3) The order of cohesion is soft rock> semi-diagenetic rock of Xigeda Formation>soil. The sensitivity of the cohesion to the water content is soft rock> semi-diagenetic rock of Xigeda Formation>soil. The sensitivity of the friction angle to the water content is soil > semi-diagenetic rock of Xigeda Formation> soft rock. 4) The rocks or soils should be classified as hard soil-soft rock, with the uniaxial compressive strength between 0.2 and 3 MPa, and cohesion between 30 and 200 kPa, measured from a standard specimen (Φ 50 mm×100 mm). It is suggested that it should be distinguished from rock and soil in practical engineering application. |
| |
| Keywords: | Xigeda semi-diagenetic rock water content microstructure strength deformation index engineering classification |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《岩土力学》浏览原始摘要信息 |
| 点击此处可从《岩土力学》下载免费的PDF全文 |
