基于SEM和MIP的冻融循环对粉质黏土强度影响机制研究

doi:10.13722/j.cnki.jrme.2014.0749

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摘要冻融作用会影响土体的强度特性，以青藏铁路沿线粉质黏土为研究对象，对经历不同冻融次数的土样进行单轴抗压强度试验、扫描电子显微镜(SEM)试验和压汞(MIP)试验，通过数字图像处理技术对土样的微结构图像进行定量分析来揭示冻融循环对土体强度影响的微观机制。结果表明：随冻融循环次数的增加，土体的单轴抗压强度呈指数型降低趋势，并在冻融30次后逐渐趋于稳定；冻融作用中土体的面孔隙度、各类孔隙所占比例和孔隙分形维数都经历了波动调整期和动态稳定期2个阶段，其中面孔隙度的变化和单轴抗压强度之间呈负相关关系；冻融循环改变土体的孔隙分布，孔隙大小及孔隙密度都呈增大趋势；冻融作用过程中，土体产生贯穿的孔隙和裂隙使土颗粒骨架与颗粒特征发生改变，导致土骨架的结构性转移，受力体系发生改变，从而改变土体强度。SEM试验和MIP试验相互对比、补充，使土体微观孔隙结构研究更加准确有效。

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关键词 ：土力学, 冻融循环, 粉质黏土, 扫描电镜, 压汞法, 单轴抗压强度, 微观孔隙

Abstract：Freeze-thaw has a great influence on strength characteristics of soil. In this paper，a series of freeze-thaw test on silty clay from the Tibetan Plateau are carried out. Then the soil samples after different runs of freeze-thaw test are used to conduct uniaxial compressive strength tests，scanning electron microscope (SEM) test and mercury intrusion porosimetry(MIP) tests. Results indicated that the uniaxial compressive strength decrease with the increase of freeze-thaw cycles and then keep stable until 30 times of freeze-thaw cycles. Microscopic pore structure parameters including plane porosity，the proportion of four kinds of pore and fractal dimension of pore experience fluctuant adjustment stage and dynamic balance stage during the freeze-thaw cycles. There is a negative correlation between the uniaxial compressive strength and plane porosity. The pore size distribution has changed after few freeze-thaw cycles，and both the pore size and pore density increase during the cycles. During the freeze-thaw cycles，some connected pores and cracks develop in the soil samples. These pore and crack changed the grain skeleton and particle characteristics of the soil，leading to changes in the soil structure and mechanical system. And consequently，the strength of the soil sample decreases. Comparison and combination between SEM tests and MIP tests make the study of soil micro-structure more accurate and effective.

Key words： soil mechanics freeze-thaw cycles silty clay SEM MIP uniaxial compressive strength micro-pore structure

引用本文:

张英1，2，邴慧1，杨成松1. 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(s1): 3597-3603.
ZHANG Ying1，2，BING Hui1，YANG Chengsong1. INFLUENCES OF FREEZE-THAW CYCLES ON MECHANICAL PORPERTIES OF SILTY CLAY BASED ON SEM AND MIP TEST. , 2015, 34(s1): 3597-3603.

链接本文:

http://www.rockmech.org/CN/10.13722/j.cnki.jrme.2014.0749 或 http://www.rockmech.org/CN/Y2015/V34/Is1/3597

[4]	齐吉琳，程国栋，VERMEER P A. 冻融作用对土工程性质影响的研究现状[J]. 地球科学进展，2005，20(8)：887-895.(QI Jinlin，CHENG Guodong，VERMEER P A. State-of-the-art of influence of freeze-thaw on engineering properties of soils[J]. Advances in Earth Science，2005，20(8)：887-895.(in Chinese))
[10]	王宝军，施斌，唐朝生. 基于GIS实现黏性土颗粒形态的三维分形研究[J]. 岩土工程学报，2007，29(2)：309-312.(WANG Baojun，SHI Bin，TANG Chaosheng. Study on 3D fractal dimension of clayey soil by use of GIS[J]. Chinese Journal of Geotechnical Engineering，2007，29(2)：309-312.(in Chinese))
[12]	中华人民共和国国家标准编写组. GB/T 50123—1999土工试验方法标准[S]. 北京：中国计划出版社，1999.(The National Standards Compilation Group of People?s Republic of China. GB/T 50123—1999 Standard for soil test method[S]. Beijing：China Planning Press，1999.(in Chinese)) " target="_blank">
[14]	张季如，祝杰，黄丽，等. 土壤微观结构定量分析的IPP图像技术研究[J]. 武汉理工大学学报，2008，30(4)：80-84.(ZHANG Jiru，ZHU Jie，HUANG Li，et al. IPP image technique used for quantitative analysis of soil microstructure[J]. Journal of Wuhan University of Technology，2008，30(4)：80-84.(in Chinese)) " target="_blank">
[2]	ALKIRE B D，MORRISON J M. Change in soil structure due to freeze-thaw and repeated loading[J]. Transportation Research Record，1983，(918)：15-21. " target="_blank">
[5]	王大雁，马巍，常小晓，等. 冻融循环作用对青藏黏土物理力学性质的影响[J]. 岩石力学与工程学报，2005，24(23)：4 313-4 319. (WANG Dayan，MA Wei，CHANG Xiaoxiao，et al. Physico- mechanical properties changes of Qinghai—Tibet clay due to cyclical freezing and thawing[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(23)：4 313-4 319.(in Chinese)) " target="_blank">
[7]	TOVEY N K，SMART P，Hounslow M W，et al. Automatic orientation mapping of some types of soil fabric[J]. Geoderma，1992，53(3)：179-200. " target="_blank">
[13]	王宝军，施斌，刘志彬，等. 基于GIS的黏性土微观结构的分形研究[J]. 岩土工程学报，2004，26(2)：244-247.(WANG Baojun，SHI Bin，LIU Zhibin，et al. Fractal study on microstructure of clayey soil by GIS[J]. Chinese Journal of Geotechnical Engineering，2004，26(2)：244-247.(in Chinese))
[8]	齐吉琳，马巍. 冻融作用对超固结土强度的影响[J]. 岩土工程学报，2006，28(12)：2 082-2 086.(QI Jilin，MA Wei. Influence of freezing-thawing on strength of overconsolidated soils[J]. Chinese Journal of Geotechnical Engineering，2006，28(12)：2 082-2 086.(in Chinese)) " target="_blank">
[11]	张先伟，孔令伟，郭爱国，等. 基于 SEM 和 MIP 试验结构性黏土压缩过程中微观孔隙的变化规律[J]. 岩石力学与工程学报，2012，31(2)：406-412.(ZHANG Xianwei，KONG Lingwei，GUO Aiguo，et al. Evolution of microscopic pore of structured clay in compression process base on SEM and MIP test[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(2)：406-412.(in Chinese))
[1]	VAN KLAVEREN R W. Hydraulic erosion resistance of thawing soil [Ph. D. Thesis][D]. Washington，USA：Department of Agricultural Engineering，Washington State University，1987. " target="_blank">
[3]	马巍，徐学祖，张立新. 冻融循环对石灰粉土剪切强度特性的影响[J]. 岩土工程学报，1999，21(2)：23-25.(MA Wei，XU Xuezu，ZHANG Lixin. Influence of frost and thaw cycles on shear strength of lime silt[J]. Chinese Journal of Geotechnical Engineering，1999，21(2)：23-25.(in Chinese))
[6]	QI J L，MA W，SONG C X. Influence of freeze-thaw on engineering properties of a silty soil[J]. Cold Regions Science and Technology，2008，53(3)：397-404. " target="_blank">
[9]	ZHANG S J，LAI Y M，ZHANG X F，et al. Study on the damage propagation of surrounding rock from a cold-region tunnel under freeze-thaw cycle condition[J]. Tunneling and Underground Space Technology，2004，19(3)：295-302.
[15]	唐朝生，施斌，王宝军. 基于SEM土体微观结构研究中的影响因素分析[J]. 岩土工程学报，2008，30(4)：56-62.(TANG Chaosheng，SHI Bin，WANG Baojun. Factors affecting analysis of soil microstructure using SEM[J]. Chinese Journal of Geotechnical Engineering，2008，30(4)：56-62.(in Chinese)) " target="_blank">