温度梯度冻土蠕变变形规律和非均质特征

赵晓东; 周国庆

doi:10.11779/CJGE201402017

温度梯度冻土蠕变变形规律和非均质特征 English Version

中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州 221008

基金项目: 973计划项目（2012CB026103）; 国家自然科学基金项目（51304209）; 中央高校基本科研业务费专项资金项目（2011QNA03）; 中国博士后基金项目（20110491489）

详细信息

作者简介:
赵晓东(1981- )，男，河北承德人，博士，副研究员，主要从事冻土力学与工程方面的研究。E-mail: zxdcumt@126.com。

中图分类号: TU445
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出版历程
- 收稿日期: 2013-04-25
- 发布日期: 2014-02-20

Creep deformation and heterogeneous characteristics for frozen soils with thermal gradient

State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221008, China

摘要

摘要: 采用K₀DCGF（K₀固结—保持荷载冻结—形成温度梯度—再试验）方法,开展不同温度梯度冻结饱和黏土三轴蠕变试验,研究冻土蠕变变形规律和温度梯度诱导的冻土非均质特征。结果表明：K₀DCGF模式中温度梯度冻结饱和黏土蠕变曲线由瞬时蠕变、衰减蠕变、稳定蠕变和加速蠕变4个阶段组成；温度梯度冻土径向蠕变速率小于轴向蠕变速率；温度梯度冻土最小轴向蠕变速率与蠕变应力之间满足指数函数关系,而长期强度极限与蠕变破坏时间之间则满足对数函数关系；梯度温度冻结过程中的水分场重分布和试验后冻土变形的非均匀分布是K₀DCGF蠕变试验中“温度梯度诱导的冻土非均质性”的重要体现；蠕变试验后温度梯度冻土冷端含水量最高,密实度最大；蠕变试验后温度梯度冻土宏观径向变形/试样高度沿试样高度方向分布随蠕变应力增加由先增加后降低规律逐步演化为持续增加规律,这一现象与冻土初始瞬时蠕变速率密切相关。
- 温度梯度 /
- 冻结饱和黏土 /
- 蠕变变形 /
- 非均质
Abstract: Triaxial creep tests on frozen clay are conducted by using the K₀DCGF (K₀ consolidation, freezing with non-uniform temperature under loading) method under various thermal gradients. The creep deformation and heterogeneous characteristics of the frozen clay with thermal gradient are investigated. The test results indicate that the frozen saturated clay with thermal gradient presents brittle characteristics in creep tests, and the creep curves are composed of transient creep stage, attenuation creep stage and accelerated creep stage. The radial creep rate is smaller than the axial one. The relationship between the minimum axial creep rate and the creep stress can be expressed by the exponential equation, while that between the long-term strength and the creep failure time can be described by the logarithmic equation. The redistribution of the water content before tests and the non-uniform deformation distribution after tests are the specific form of the heterogeneous characteristics caused by the thermal gradient. The water content and the density at the lower temperature end are the largest. The ratio between the radial deformation and the specimen height increases as the specimen height increases, and it decreases as the specimen height increases further under lower creep stress. However, the ratio between the radial deformation and the specimen height presents a continuous increase trend as the specimen height increases under higher creep stress. This phenomenon is related to the initial transient creep rate.
- thermal gradient /
- frozen saturated clay /
- creep deformation /
- heterogeneous characteristic

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参考文献(12)

[1]	ZHAO X D, ZHOU G Q, CHEN G Z, et al. Triaxial compression deformation for artificial frozen clay with thermal gradient[J]. Cold Regions Science and Technology, 2011, 67(3): 171-177.
[2]	ZHAO X D, ZHOU G Q, CHEN G Z. Triaxial compression strength for artificial frozen clay with thermal gradient[J]. Journal of Central South University of Technology, 2013, 20(1): 218-225.
[3]	赵晓东, 周国庆, 陈国舟. 温度梯度冻结黏土破坏特征及抗压强度分析[J]. 岩土工程学报, 2010, 32(12): 1856-1860. (ZHAO Xiao-dong, ZHOU Guo-qing, CHEN Guo-zhou. Failure mode and compression strength for frozen clay with thermal gradient[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(12): 1856-1860. (in Chinese))
[4]	赵晓东, 周国庆, 商翔宇, 等. 温度梯度冻土压缩破坏特征及能量规律[J]. 岩土工程学报, 2012, 34(12): 2350-2354. (ZHAO Xiao-dong, ZHOU Guo-qing, SHANG Xiang-yu, et al. Deformation failure and energy properties for frozen soil with thermal gradient[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(12): 2350-2354. (in Chinese))
[5]	周国庆, 赵晓东, 李生生. 不同温度梯度两种路径冻结中砂应力-应变特性试验研究[J]. 岩土工程学报, 2010, 32(3): 338-343. (ZHOU Guo-qing, ZHAO Xiao-dong, LI Sheng-sheng. Stress-strain properties for the frozen media sand at different temperature gradients during two stress paths[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(3): 338-343. (in Chinese))
[6]	王大雁, 马巍, 常小晓. K₀固结后卸载状态下冻土应力-应变特性研究[J]. 岩石力学与工程学报, 2004, 23(8): 1252-256. (WANG Da-yan, MA Wei, CHANG Xiao-xiao. Study on behavior of stress-strain of frozen soils subjected to K₀consolidation by unloading triaxial shear tests[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(8): 1252-256. (in Chinese))
[7]	马巍, 吴紫汪, 常小晓. 固结过程对冻土应力-应变特性的影响[J]. 岩土力学, 2000, 21(3): 198-200. (MA Wei, WU Zi-wang, CHANG Xiao-xiao. Effects of consolidation process on stress-strain characters of tjaeles[J]. Rock and Soil Mechanics, 2000, 21(3): 198-200. (in Chinese))
[8]	王建州. 深厚表土层非均质厚冻结壁力学特性研究[D]. 徐州: 中国矿业大学, 2008. (WANG Jian-zhou. Research on the mechanical properties of inhomogeneous thick frozen wall in deep alluvium[D]. Xuzhou: China University of Mining and Technology, 2008. (in Chinese))
[9]	陈军浩. 多圈管冻结壁的形成与融化规律研究[D]. 淮南:安徽理工大学, 2010. (CHEN Jun-hao. Study on the law of forming and thawing of frozen wall with multi-freezing-tube[D]. Huainan: Anhui University of Science and Technology, 2010. (in Chinese))
[10]	ZHAO X D, ZHOU G Q. Experimental study on the creep behavior of frozen clay with thermal gradient[J]. Cold Regions Science and Technolgoy, 2013, 86(2): 127-132.
[11]	吴紫汪. 青藏冻土研究论文集[M]. 北京: 科学出版社, 1983. (WU Zi-wang. Research theses on frozen soil in Qinghai Tibetan plateau[M]. Beijing: Science Press, 1983. (in Chinese))
[12]	商翔宇. 不同应力水平下深部粘土力学特性研究[D]. 徐州: 中国矿业大学, 2009. (SHANG Xiang-yu. Study on the mechanical properties of deep clay[D]. Xuzhou: China University of Mining and Technology, 2009. (in Chinese))