结构性黄土双轴压缩试验的离散元数值仿真分析

蒋明镜; 李涛; 胡海军

结构性黄土双轴压缩试验的离散元数值仿真分析 English Version

蒋明镜^{1, 2},
李涛^{1, 2},
胡海军³

1. 同济大学地下建筑与工程系,上海 200092; 2. 同济大学岩土及地下工程教育部重点实验室,上海 200092; 3. 西北农林科技大学水利与建筑工程学院,陕西杨凌 712100

详细信息

作者简介:
蒋明镜(1965- )，男，教授，博士生导师，国家杰出青年基金获得者，主要从事天然结构性黏土、砂土、非饱和土、太空土和深海能源土宏观微观试验、本构模型和数值分析研究。E-mail: mingjing.jiang@tongji.edu.cn。

中图分类号: TU444
计量
- 文章访问数: 327
- HTML全文浏览量: 2
- PDF下载量: 481
出版历程
- 收稿日期: 2013-06-06
- 发布日期: 2013-11-24

Numerical simulation of biaxial tests on structured loess by distinct element method

JIANG Ming-jing^{1, 2},
LI Tao^{1, 2},
HU Hai-jun³

1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical & Underground Engineering. Ministry of Education, Tongji University, Shanghai 200092, China; 3. College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China

摘要

摘要: 通过建立胶结强度与初始含水率之间的关系将含水率引入胶结接触模型,并将其应用于饱和重塑土和不同含水率结构性黄土离散元试样的常规双轴试验数值模拟中。结果表明：结构性黄土离散元试样双轴试验的宏观力学行为与天然结构性黄土室内三轴试验结果相似。即围压越低,含水率越低,则试样越容易表现出应变软化和剪胀；反之则试样越容易表现为应变硬化和剪缩。该宏观力学行为与试样粒间胶结破坏密切相关。即围压越低,含水率越低,则试样固结过程产生的胶结破坏越少,后续胶结破坏对试样宏观力学行为影响较大,试样越容易表现出应变软化和剪胀。
- 黄土 /
- 结构性土 /
- 胶结颗粒材料 /
- 离散单元法 /
- 双轴试验
Abstract: A relationship between the bond strength and the initial water content is established and used to incorporate water content to a bond contact model. Then using this model, various numerical biaxial tests on remolded and structured loess samples with different water contents are carried out by means of the distinct element method. The following conclusions can be drawn from these simulations. The macro-mechanical behaviors of biaxial tests on numerical and natural loess samples are similar. That is, as the confining pressure and initial water content decrease, the samples exihibit much strain softening and shear dilatancy. As the confining pressure and initial water content increase, however, the samples perform much strain hardening and shear contraction. The macro-mechanical behaviors are associated with the inter-particle bond breakage. Because fewer bonds of samples with lower confining pressure and initial water content are broken in the consolidation, the bonds affect biaxial compression more and the samples exhibit strain softening and shear dilatancy relatively.
- loess /
- structured soil /
- cemented granular matter /
- distinct element method /
- biaxial test

HTML全文

参考文献(14)

[1]	GAO G R. The distribution and geotechnical properties of loess soils, lateritic soils and clayey soils in China[J]. Engineering Geology, 1996, 42(1): 95-104.
[2]	蒲毅彬, 陈万业, 廖全荣. 陇东黄土湿陷过程的CT结构变化研究[J]. 岩土工程学报, 2000, 22(1): 49-54. (PU Yi-bin, CHEN Wan-ye, LIAO Quan-rong. Research on CT structure changing for damping process of loess in Longdong[J]. Chinese Journal of Geotechnical Engineering, 2000, 22(1): 49-54. (in Chinese))
[3]	CUNDALL P A, STRACK O D L. The distinct element method as a tool for research in granular media, Part Ⅰ[R]. Minnesota: University of Minnesota, 1978: 1-97.
[4]	JIANG M J, YU H S, LEROUEIL S. A simple and efficient approach to capturing bonding effect in naturally microstructured sands by discrete element method[J]. International Journal for Numerical Methods in Engineering, 2007, 69(6): 1158-1193.
[5]	JIANG M J, KONRAD J M, LEROUEIL S. An efficient technique for generating homogeneous specimens for DEM studies[J]. Computers and Geotechnics, 2003, 30(7): 579-597.
[6]	JIANG M J, LEROUEIL S, KONRAD J M. Insight into shear strength functions of unsaturated granulates by DEM analyses[J]. Computers and Geotechnics, 2004, 31(6): 473-489.
[7]	LIU S H, SUN D A, WANG Y S. Numerical study of soil collapse behavior by discrete element modelling[J]. Computers and Geotechnics, 2003, 30(5): 399-408.
[8]	蒋明镜, 胡海军, 彭建兵. 结构性黄土一维湿陷特性的离散元数值模拟[J]. 岩土力学, 2013, 34(4): 1121-1130. (JIANG Ming-jing, HU Hai-jun, PENG Jian-bing. Simulation of collapsible behavior of structural loess under one-dimensional condition by discrete element method (DEM)[J]. Rock and Soil Mechanics, 2013, 34(4): 1121-1130. (in Chinese))
[9]	胡再强, 沈珠江, 谢定义. 非饱和黄土的结构性研究[J]. 岩石力学与工程学报, 2000, 19(6): 775-779. (HU Zai-qiang, SHEN Zhu-jiang, XIE Ding-yi. Research on structural behavior of unsaturated loess[J]. Chinese Journal of Rock Mechanics and Engineering, 2000, 19(6): 775-779. (in Chinese))
[10]	陈立, 李靖, 王俊卿, 等. 黄土的结构强度及其与结构屈服压力的关系[J]. 岩土工程学报, 2008, 30(6): 895-899. (CHEN Li, LI Jing, WANG Jun-qing, et al. Relationship between structural strength and structural yield pressure of loess[J]. Chinese Journal of Geotechnical Engineering, 2008, 30(6): 895-899. (in Chinese))
[11]	夏旺民. 黄土弹塑性损伤本构模型及工程应用研究[D]. 西安: 西安理工大学, 2005. (XIA Wang-min. The elasto-plastic damage constitutive model of loess and its engineering application[D]. Xi'an: Xi'an University of Technology, 2005. (in Chinese))
[12]	陈宗基. 我国西北黄土的基本性质及其工程性质[J]. 岩土工程学报, 1989, 11(6): 9-23. (TAN Tjong-kie. Fundamental properties of loess from northwestern China[J]. Chinese Journal of Geotechnical Engineering, 1989, 11(6): 9-23.(in Chinese))
[13]	邵生俊, 龙吉勇, 于清高, 等. 湿陷性黄土的结构性参数本构模型[J]. 水利学报, 2006, 37(11): 1315-1322. (SHAO Sheng-jun, LONG Ji-yong, YU Qing-gao, et al. A constitutive model of collapsible loess with structural parameter[J]. Rock and Soil Mechanics, 2006, 37(11): 1315-1322. (in Chinese))
[14]	胡海军, 蒋明镜. 等吸力下非饱和重塑土三轴剪切试验离散元数值模拟[C]// 全国土木工程博士生学术论坛优秀论文集. 长沙: 中南大学出版社, 2010. (JIANG Ming-jing, HU Hai-jun. Triaxial shear tests simulation of unsaturated remolded soil under constant suction by DEM analysis[C]// Proceedings of National Civil Engineering Forum for Ph.D Students. Changsha: Central South University Press, 2010. (in Chinese))