| Citation: |
GU Di, YAN Xuexin, ZHANG Yun, BAI Yang, YANG Tianliang. Micro-mechanism of compression and rebound of clay in Shanghai[J]. Hydrogeology & Engineering Geology, 2020, 47(4): 123-131. DOI: 10.16030/j.cnki.issn.1000-3665.201912022
|
Previous micro-mechanism for clay deformation was focused on the compression. With the researches moving on, more attention has been paid to the micro-mechanism for clay rebounding. However, little relevant research has been done until now. The microscopic characteristics and their changes for both compression and rebound of the Shanghai clay are investigated in this paper through odometer tests, scanning electron microscope, and mercury intrusion porosimetry. The test results show that the change in micro-structure parameters can represent the macroscopic characteristics of clay deformation. When loaded, with the increasing consolidation pressure, the pore volume of clay decreases, the number of pores first increases and then decreases, the average pore shape coefficient increases first greatly and then slowly, and the pore shape fractal dimension first decreases greatly and then slowly. When unloaded, with the decreasing pressure, the number of pores increases, the average pore shape coefficient gently decreases, and pore shape fractal dimension slightly increases. In the compressing process, the percentages of medium and small pores change a little when the pressure is small, while the percentage of small pores increases greatly and that of medium pores decreases clearly when the pressure is great. In the rebounding process, the small pores are predominant under all levels of pressure, however, the percentage of medium pores is great for great pressure and it is small for small pressure. The rebound of clay results primarily from the increasing volume of small pores.
| [1] |
李越, 孙红, 葛修润. 固结条件下上海软土微观特征研究[J]. 河北工程大学学报(自然科学版), 2018, 35(1): 9-13.
LI Y, SUN H, GE X R. Study on microcosmic characteristics of Shanghai soft soil under consolidation[J]. Journal of Hebei University of Engineering (Natural Science Edition), 2018, 35(1): 9-13. (in Chinese)
|
| [2] |
周晖, 房营光, 禹长江. 广州软土固结过程微观结构的显微观测与分析[J]. 岩石力学与工程学报, 2009, 28(增刊2): 3830-3837.
ZHOU H, FANG Y G, YU C J. Micro-structure observation and analysis of Guangzhou soft soil during consolidation process[J]. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(Sup 2): 3830-3837. (in Chinese)
|
| [3] |
谢晓华, 周永章, 张澄博, 等. 珠三角饱和软土固结过程中微观孔隙结构的演化规律[J]. 桂林理工大学学报, 2010, 30(3): 368-373. DOI: 10.3969/j.issn.1674-9057.2010.03.009
XIE X H, ZHOU Y Z, ZHANG C B, et al. Evolution of microscopic pore structure under saturated soft soil consolidation process in Pearl River Delta[J]. Journal of Guilin University of Technology, 2010, 30(3): 368-373. (in Chinese) DOI: 10.3969/j.issn.1674-9057.2010.03.009
|
| [4] |
孔令荣, 黄宏伟, 张冬梅, 等. 不同固结压力下饱和软粘土孔隙分布试验研究[J]. 地下空间与工程学报, 2007, 3(6): 1036-1040. DOI: 10.3969/j.issn.1673-0836.2007.06.012
KONG L R, HUANG H W, ZHANG D M, et al. Experiment study on relationship between pore distribution and different stress levels due to consolidation of soft clays[J]. Chinese Journal of Underground Space and Engineering, 2007, 3(6): 1036-1040. (in Chinese) DOI: 10.3969/j.issn.1673-0836.2007.06.012
|
| [5] |
周建, 邓以亮, 曹洋, 等. 杭州饱和软土固结过程微观结构试验研究[J]. 中南大学学报(自然科学版), 2014, 45(6): 1998-2005.
ZHOU J, DENG Y L, CAO Y, et al. Experimental study of microstructure of Hangzhou saturated soft soil during consolidation process[J]. Journal of Central South University (Science and Technology), 2014, 45(6): 1998-2005. (in Chinese)
|
| [6] |
杨爱武, 吴可龙, 周玉明, 等. 小偏应力作用下吹填土蠕变过程中微结构特征演变研究[J]. 水文地质工程地质, 2015, 42(2): 89-96.
YANG A W, WU K L, ZHOU Y M, et al. A study of the microstructure characteristics evolution of dredger fill in the process of creep[J]. Hydrogeology & Engineering Geology, 2015, 42(2): 89-96. (in Chinese)
|
| [7] |
张英, 邴慧, 杨成松. 基于SEM和MIP的冻融循环对粉质黏土强度影响机制研究[J]. 岩石力学与工程学报, 2015, 34(增刊1): 3597-3603.
ZHANG Y, BING H, YANG C S. Influences of freeze-thaw cycles on mechanical properties of silty clay based on SEM and MIP test[J]. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(Sup 1): 3597-3603. (in Chinese)
|
| [8] |
白冰, 周健. 扫描电子显微镜测试技术在岩土工程中的应用与进展[J]. 电子显微学报, 2001, 20(2): 154-160.
BAI B, ZHOU J. The applications and advances of SEM in geotechnical engineering[J]. Journal of Chinese Electron Microscopy Society, 2001, 20(2): 154-160. (in Chinese)
|
| [9] |
LIU C, SHI B, ZHOU J, et al. Quantification and characterization of microporosity by image processing, geometric measurement and statistical methods: Application on SEM images of clay materials[J]. Applied Clay Science, 2011, 54(1): 97-106. DOI: 10.1016/j.clay.2011.07.022
|
| [10] |
孟庆山, 杨超, 许孝祖, 等. 动力排水固结前后软土微观结构分析[J]. 岩土力学, 2008, 29(7): 1759-1763. DOI: 10.3969/j.issn.1000-7598.2008.07.006
MENG Q S, YANG C, XU X Z, et al. Analysis of microstructure of soft clay before and after its improvement with dynamic consolidation by drainage[J]. Rock and Soil Mechanics, 2008, 29(7): 1759-1763. (in Chinese) DOI: 10.3969/j.issn.1000-7598.2008.07.006
|
| [11] |
MOORE C A, DONALDSON C F. Quantifying soil microstructure using fractals[J]. Géotechnique, 1995, 45(1): 105-116. DOI: 10.1680/geot.1995.45.1.105
|
| [12] |
陈波, 孙德安, 高游, 等. 上海软黏土的孔径分布试验研究[J]. 岩土力学, 2017, 38(9): 2523-2530.
CHEN B, SUN D A, GAO Y, et al. Experimental study of pore-size distribution of Shanghai soft clay[J]. Rock and Soil Mechanics, 2017, 38(9): 2523-2530. (in Chinese)
|
| 1. |
赵洲，宋晶，刘锐鸿，杨守颖，李志杰. 各向异性对软土力学特性影响的离散元模拟. 水文地质工程地质. 2021(02): 70-77 .
 本站查看
|
Supported by:
Beijing Renhe Information Technology Co., Ltd. 
Email Alert
RSS
DownLoad: