冻土二元介质模型探讨——以-6℃冻结粉土为例

张德; 刘恩龙; 刘星炎; 宋丙堂

doi:10.11779/CJGE201801007

冻土二元介质模型探讨——以-6℃冻结粉土为例 English Version

张德^1,2,
刘恩龙^1,3, ,,
刘星炎^1,2,
宋丙堂^1,2

1.中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000
2.中国科学院大学,北京 100049
3.四川大学水利水电学院,四川成都 610065

基金项目: 中国科学院“百人计划”项目; 国家自然科学基金项目（41771066）

详细信息

作者简介:
张德(1987-),男,四川德阳人,博士研究生,主要从事冻土本构模型研究。E-mail：120821875@qq.com。

通讯作者:
刘恩龙，E-mail：liuenlong@scu.edu.cn

中图分类号: TU445
计量
- 文章访问数: 0360
- HTML全文浏览量: 0
- PDF下载量: 0401
出版历程
- 收稿日期: 2016-11-06
- 发布日期: 2018-01-24

Investigation on binary medium model taking frozen silt soils under -6℃ for example

1.Northwest Institute of Eco-Environment and Resources, State Key Laboratory of Frozen Soil Engineering, Chinese Academy of Sciences, Lanzhou 730000, China
2.University of Chinese Academy of Sciences, Beijing 100049, China
3.College of Water Resources and Hydropower, Sichuan University, Chengdu 610065, China

摘要

摘要: 二元介质模型已成功用于模拟未冻结岩土材料,比如岩石、均质或各向异性结构性土、超固结黏土、堆石料以及黄土。类似地,为了探讨冻土的应力应变关系,此处引入二元介质模型来模拟其应力应变关系。基于岩土破损力学理论框架和二元介质模型概念,将饱和冻结粉土抽象成具有强胶结特性的胶结元（冻土骨架）和无胶结特性的摩擦元（融土骨架）,胶结元在一定围压下会产生压碎和压融现象,随围压的增大逐步破损并向摩擦元转化,二者共同承担外荷载。在-6℃和0.3~15.0 MPa围压下对冻结粉土进行了一系列低温三轴压缩试验,结果表明：随变形的增大,应力应变曲线均呈三阶段变化,分别是线弹性阶段、弹塑性阶段和应变软化阶段;强度随围压的增大呈先增大后减小的趋势,极限强度对应下的围压称为临界围压,且临界围压下的软化现象最不明显。通过细观角度运用二元介质模型概念探讨了冻土变形破损机理,在非均质材料均匀化理论基础上建立了冻土二元介质模型,讨论了破损率函数演化规律。理论与试验结果对比表明,所建立的模型可以较好地模拟冻土的应变硬化和软化现象。
- 岩土破损力学 /
- 冻结粉土 /
- 二元介质模型 /
- 破损机制 /
- 胶结元 /
- 摩擦元
Abstract: The binary medium model (abbreviated as BMM) is suitable for unfrozen geomaterials, such as rock, isotropic or anisotropic structured soils, overconsolidated clay, rockfill materials and loess, and has a good accuracy and satisfactory applicability. Similarly, in order to investigate the stress-strain relationship of frozen soils, the BMM is introduced and employed to simulate the deformation characteristics. Based on the theoretical framework of breakage mechanics for geomaterials and the concept of BMM, the saturated frozen silt soils are conceptualized as the binary medium consisting of bonding blocks with strong bonding (the frozen soil skeleton) and frictional elements without weakened bonding (the melted soil skeleton), and the bonding elements will be crushed, melted and gradually transformed to frictional elements with the increasing confining pressure during the loading process, resulting two of the bonding blocks and weakened bands bear the external loads, collectively. A series of cryogenic triaxial compressive tests are conducted at -6℃ under confining pressure of 0.3 to 15.0 MPa, and the following test results demonstrate that the stress-strain curves behave three varying stages with the increasing axial strain, which are the initial linear elastic stage, elasto-plastic stage and strain softening stage, respectively. The strength of frozen soils increases first and then decreases with the further increase of confining pressures. The critical confining pressure corresponds to the peak strength for different test curves, under which the strain softening phenomenon is less obvious. From a mesoscopic point of view, the deformation and damage mechanisms of frozen soils are investigated based on the concept of binary medium, and the stress-strain formulation is established on the basis of the homogenization theory of the heterogeneous materials. Finally, the evolution of breakage function is analyzed and discussed through determination of the
- breakage mechanics for geomaterials /
- frozen silt soil /
- binary medium model /
- breakage mechanism /
- bonding element /
- frictional element

HTML全文

参考文献(24)

[1]	马巍, 王大雁. 中国冻土力学研究50 a回顾与展望[J]. 岩土工程学报, 2012, 34(4): 625-640. (MA Wei, WANG Da-yan.Studies on frozen soil mechanics in China in past 50 years and their prospect[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(4): 625-640. (in Chinese))
[2]	齐吉琳, 马巍. 冻土的力学性质及研究现状[J]. 岩土力学, 2010, 31(11):133-143. (QI Ji-lin, MA Wei.State-of-art of research on mechanical properties of frozen soils[J]. Rock and Soil Mechanics, 2010, 31(11): 133-143. (in Chinese))
[3]	LAI Y M, LIAO M K, HU K.A constitutive model of frozen saline sandy soil based on energy dissipation theory[J]. International Journal of Plasticity, 2016, 78(3): 84-113.
[4]	LAI Y M, JIN L, CHANG X X.Yield criterion and elasto- plastic damage constitutive model for frozen sandy soil[J]. International Journal of Plasticity, 2009, 25(6): 1177-1205.
[5]	LAI Y M, YANG Y G, CHANG X X, et al.Strength criterion and elastoplastic constitutive model of frozen silt in generalized plastic mechanics[J]. International Journal of Plasticity, 2010, 26(10): 1461-1484.
[6]	沈珠江, 陈铁林. 岩土破损力学:基本概念、目标和任务[C]// 中国岩石力学与工程大会第七次学术大会. 西安, 2002: 9-12. (SHEN Zhu-jiang, CHEN Tie-lin.Breakage mechanics for geological materials basic concepts, goal and task[C]// Proceeding of 7th Conference on Rock Mechanics and Project. Xi'an, 2002: 9-12. (in Chinese))
[7]	沈珠江. 岩土破损力学与双重介质模型[J]. 水利水运工程学报, 2002(4): 1-6. (SHEN Zhu-jiang.Breakage mechanics and binary medium model for geological materials[J]. Hydro-Science and Engineering, 2002(4): 1-6. (in Chinese))
[8]	沈珠江, 刘恩龙, 陈铁林. 岩土二元介质模型的一般应力应变关系[J]. 岩土工程学报, 2005, 27(5): 489-494. (SHEN Zhu-jiang, LIU En-long, CHEN Tie-lin.Generalized stress strain relationship of binary medium model for geological materials[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(5): 489-494. (in Chinese))
[9]	刘恩龙, 张建海, 何思明, 等. 循环荷载作用下岩石的二元介质模型[J]. 重庆理工大学学报, 2013, 27(9): 6-12. (LIU En-long, ZHANG Jian-hai, HE Si-ming, et al.Binary medium model of rock subjected to cyclic loading[J]. Journal of Chongqing University of Technology, 2013, 27(9):6-12. (in Chinese))
[10]	刘恩龙, 黄润秋, 何思明. 岩样变形特性的二元介质模拟[J]. 水利学报, 2012, 43(10):1237-1245. (LIU En-long, HUANG Run-qiu, HE Si-ming.Modeling the deformation properties of rock samples by binary medium model[J]. Journal of Hydraulic Engineering, 2012, 43(10):1237-1245. (in Chinese))
[11]	刘恩龙, 覃燕林, 陈生水, 等. 堆石料的临界状态探讨[J]. 水利学报, 2012, 43(5): 505-511, 519.(LIU En-long, TAN Yan-lin, CHEN Sheng-shui, et al. Investigation on critical state of rockfill materials[J].Journal of Hydraulic Engineering, 2012, 43(5): 505-511, 519. (in Chinese))
[12]	刘恩龙. 岩土结构块破损机制与二元介质模型研究[D]. 北京: 清华大学, 2005. (LIU En-long.Research on breakage mechanism of structural blocks and binary medium model for geomaterials[D]. Beijing: Tsinghua University, 2005. (in Chinese))
[13]	刘恩龙, 沈珠江. 结构性土的二元介质模型[J]. 水利学报, 2005, 36(4): 391-395. (LIU En-long, SHEN Zhu-jiang.Binary medium model for structured soils[J]. Journal of Hydraulic Engineering, 2005, 36(4): 391-395. (in Chinese))
[14]	刘恩龙, 沈珠江. 基于二元介质模型的岩土类材料破损过程数值模拟[J]. 水利学报, 2006, 37(6): 721-726. (LIU En-long, SHEN Zhu-jiang.Simulation of breakage processes of geomaterials by binary-medium model[J]. Journal of Hydraulic Engineering, 2006, 37(6): 721-726. (in Chinese))
[15]	刘恩龙, 罗开泰, 张数祎. 初始应力各向异性结构性土的二元介质模型[J]. 岩土力学, 2013, 34(11): 3103-3109. (LIU En-long, LUO Kai-tai, ZHANG Shu-yi.Binary medium model for structured soils with initial stress-induced anisotropy[J]. Rock and Soil Mechanics, 2013, 34(11): 3103-3109. (in Chinese))
[16]	刘恩龙, 沈珠江. 岩土材料不同应力路径下脆性变化的二元介质模拟[J]. 岩土力学, 2006, 27(2): 261-267. (LIU En-long, SHEN Zhu-jiang.Binary medium modeling of the brittleness variety of geomaterials under different stress paths[J]. Rock and Soil Mechanics, 2006, 27(2): 261-267. (in Chinese))
[17]	沈珠江, 胡再强. 黄土的二元介质模型[J]. 水利学报, 2003, 34(7): 1-6. (SHEN Zhu-jiang, HU Zai-qiang.Binary medium modelfor loess[J]. Journal of Hydraulic Engineering, 2003, 34(7):1-6. (in Chinese))
[18]	卢全中, 彭建兵, 王水林, 等. 裂隙性黄土的双参数二元介质模型[J]. 岩土工程学报, 2012, 34(5): 893-898. (LU Quan-zhong, PENG Jian-bing, WANG Shui-lin, et al.Double-parameter binary-medium model for fissured loess[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(5): 893-898. (in Chinese))
[19]	范文, 闫芙蓉, 邓龙胜, 等. 裂隙黄土的单参数二元介质模型[J]. 岩土工程学报, 2009, 31(11): 1752-1756. (FAN Wen, YAN Fu-rong, DENG Long-sheng, et al.Single parameter binary-medium model of fissured loess[J]. Chinese Journal of Geotechnical Engineering, 2009, 31(11): 1752-1756. (in Chinese))
[20]	李宏儒, 胡再强, 冯飞, 等. 结构性黄土二元介质本构模型在局部化剪切带中的应用[J]. 岩土力学, 2012, 33(9): 2803-2810. (LI Hong-ru, HU Zai-qiang, FENG Fei, et al.Application of structural loess binary-medium model to localization shear band[J]. Rock and Soil Mechanics, 2012, 33(9): 2803-2810. (in Chinese))
[21]	李宏儒, 胡再强, 赵凯, 等. 结构性土二元介质本构模型及破损率影响因素的研究[J]. 岩土力学, 2012, 33(增刊1): 67-72. (LI Hong-ru, HU Zai-qiang, ZHAO Kai, et al.Structural soil binary-medium constitutive model and factor of breakage ratio influence[J]. Rock and Soil Mechanics, 2012, 33(S1): 67-72. (in Chinese))
[22]	LIU E L.Breakage and deformation mechanisms of crushable granular materials[J]. Computers and Geotechnics, 2010, 37(5): 723-730.
[23]	马巍, 吴紫汪, 盛煜. 围压对冻土强度特性的影响[J]. 岩土工程学报, 1995, 17(5): 7-11. (MA Wei, WU Zi-wang, SHENG Yu.Effect of confining pressure on strength behavior of frozen soil[J]. Chinese Journal of Geotechnical Engineering, 1995, 17(5): 7-11. (in Chinese))
[24]	CHAVES E W.Notes on continuum mechanics[M]. Netherlands: Springer Science & Business Media, 2013