Abstract:A series of triaxial compression tests on frozen clay are conducted under various thermal gradients and consolidation pressures by means of the K0DCGF (K0 consolidation, freezing with non-uniform temperature under loading) method. The deformation failure characteristics and compression energy are investigated. The test results indicate that the frozen saturated clay with thermal gradients has brittle characteristics. However, the frozen saturated clay with uniform temperature presents the plastic characteristics. The deformation process for frozen clay with thermal gradients can be divided into three stages elastic deformation stage, micro-fissures (or micro-holes) developing stage before the axial stress reaches the peak value and the micro-fissures transfixion stage when the axial stress is greater than the peak value. The ratio of the elastic strain energy to the total input energy increases with the increase of the thermal gradients and consolidation pressures. This phenomenon is correspondent to the relationship between the brittle characteristics and the thermal gradients and consolidation pressures.
[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. Increment Poisson′ ratio for frozen clay with thermal gradient[C]// The 3rd International Conference on Heterogeneous Material Mechanics, Shanghai,2011 [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,李生生. 不同温度梯度冻结深部黏土偏应力演变规律研究[J]. 岩石力学与工程学报, 2009,28(8):1646-1651 ZHAO Xiao-dong, ZHOU Guo-qing, LI Sheng-sheng. Research on deviatoric stress variation laws for deep frozen clay at different temperature gradients[J]. Chinese Journal of Rock Mechanics and Engineering, 2009,28(8):1646-1651. (in Chinese)) [5] 赵晓东,周国庆,李生生. 不同温度冻结中砂加卸荷变形特性研究[J]. 中国矿业大学学报, 2010,39(2):158-162 ZHAO Xiao-dong, ZHOU Guo-qing, LI Sheng-sheng. Research on loading and unloading deformation properties for frozen medium sand with different thermal gradients[J]. Journal of China University of Mining and Technology, 2010,20(2):158-162. (in Chinese)) [6] ZHAO Xiao-dong, ZHOU Guo-qing, CAI Wei,et al. Effects of temperature gradients on elastic modulus and compression strength for the saturated frozen clay[C]// The 6th International Conference on Mining Science and Technology, Procedia Earth and Planetary Science, 2009: 420-424. [7] 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, 2010,20(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, 2010,20(3):338-343. (in Chinese)) [8] 赵艳华. 混凝土断裂过程中的能量分析研究[D]. 大连: 大连理工大学, 2002. ZHAO Yan-hua. The analytical study on the energy in the fracture process of concrete[D]. Dalian: Dalian University of Technology, 2002.(in Chinese)) [9] 尤明庆,华安增. 岩石试样破坏过程的能量分析[J]. 岩石力学与工程学报, 2002,21(6):778-781 YOU Ming-qing, HUA An-zeng. Energy analysis on failure process of rock specimens[J]. Chinese Journal of Rock Mechanics and Engineering, 2002,21(6):778-781. (in Chinese)) [10] 杨圣奇,徐卫亚,苏承东. 岩样单轴压缩变形破坏与能量特征研究[J]. 固体力学学报, 2006,27(2):213-216 YANG Shengg-qi, XU Wei-ya,SU Cheng-dong. Study on the deformation failure and energy properties of rock specimen in uniaxial compression[J]. Acta Mechnica Solida Sinica, 2006,27(2):213-216. (in Chinese)) [11] 杨圣奇,徐卫亚,苏承东. 大理岩三轴压缩变形破坏与能量特征研究[J]. 工程力学, 2007,24(1):136-142 YANG Shengg-qi, XU Wei-ya, SU Cheng-dong. Study on the deformation failure and energy properties of marble specimen under triaxial compression[J]. Engineering Mechanics, 2007,24(1):136-142. (in Chinese)) [12] 徐小丽,高 峰,周 清,等. 高温后岩石变形破坏过程的能量分析[J]. 武汉理工大学学报, 2011,33(1):104-107 XU Xiao-li, GAO Feng, ZHOU Qing,et al. Energy analysis of rock deformation and failure process after high temperature[J]. Journal of Wuhan University of Technology, 2011,33(1):104-107. (in Chinese)) [13] CHAMBERLAIN E, GROVES C, PERHAM R. The mechanical behavior of frozen earth materials under high pressure tri-axial conditions[J]. Géotechnique, 1972,22(3):469-483 [14] 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 K0 consolidation by unloading triaxial shear tests[J]. Chinese Journal of Rock Mechanics and Engineering, 2004,23(8):1252-256. (in Chinese))