Damage dissipation potential of frozen remolded Lanzhou loess based on CT uniaxial compression test results
ZHAO Shu-ping1, MA Wei1, ZHENG Jian-feng1, JIAO Gui-de12
1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2. Civil and Engineering Department, Lanzhou University, Lanzhou 730000, China
Abstract:The physical nature of frozen soil damage is analyzed. A series of CT scanning during the uniaxial compress test process is conducted on an enhanced triaxial system which works together with the CT system. According to the test results, the yield strain, damage strain critical value, and failure strain critical value of the frozen remolded Lanzhou loess are obtained. Then, the plastic strain is used to describe the damage threshold value. The lower the temperature, the larger the damage threshold value. In the end, the CT value is used to define damage variable, and the damage evolution law is derived based on the results of CT scanning tests. A damage potential function suitable for frozen soil is proposed.
[1] SHEN M, LADANYI B. Modeling of coupled heat, moisture and stress field in freezing soil[J]. Cold Regions Science and Technology, 1987, 14: 237-246 [2] MIAO Tian-de, WEI Xue-xia, ZHANG Chang-qing. Creep of frozen soil by damage mechanics [J]. Science in China (Series B), 1995, 38(8): 996-1002 [3] HE Ping, ZHU Yuan-lin, CHENG Guo-dong. Constitutive models of frozen soil[J]. Canadian Geotechnical Journal, 2000, 37(4): 811-816 [4] 朱志武, 宁建国, 马 巍. 基于损伤的冻土本构模型及水,热,力三场耦合数值模拟研究[J]. 中国科学: 物理学,力学,天文学, 2010, 40(6): 758-772 ZHU Zhi-wu, NING Jian-guo, MA Wei. The constitutive model of frozen soil with damage and numerical analysis for the coupled problem of water, temperature and stress fields[J]. Scientia Sinica Phys, Mech & Astron, 2010, 40(6): 758-772. (in Chinese)) [5] 杨更社, 张长庆. 岩体损伤及检测[M]. 西安: 陕西科学技术出版社, 1998. YANG Geng-she, ZHNAG Chang-qing. Detect the damage of rocks[M]. Xi'an: Shaanxi Science and Technology Press, 1998. [6] 葛修润, 任建喜, 蒲毅彬, 等. 岩土损伤力学宏细观试验研究[M]. 北京: 科学出版社, 2004. GE Xiu-run, REN Jian-xi, PU Yi-bin,,et al. Macro and Micro test research on damage mechanics of rock and soil[M]. Beijing: Science Press, 2004. [7] 仵彦卿, 丁卫华, 曹广祝. 岩石单轴与三轴CT尺度裂纹演化过程观测[J]. 西安理工大学学报, 2003, 19(2): 115-119 WU Yan-qing, DING Wei-hua, CAO Guang-zhu. Observation and detection of evolution process rock crack on CT scale under uniaxial and triaxial compression conditions[J]. Journal of Xi'an University of Technology, 2003, 19(2): 115-119. (in Chinese)) [8] 李晓军, 张登良. CT技术在土体结构性分析中的应用初探[J]. 岩土力学, 1999, 20(2): 62-66 LI Xiao-jun, ZHANG Deng-liang. Application of CT in analysis of structure of compacted soil [J]. Rock and Soil Mechanics, 1999, 20(2): 62-66. (in Chinese)) [9] 卢再华, 陈正汉, 蒲毅彬. 原状膨胀土损伤演化的三轴CT试验研究[J]. 水利学报, 2002(6): 106-112 LU Zai-hua, CHEN Zheng-han, PU Yi-bin. Study on damage evolution of natural expansive soil with computerized tomography during triaxial shear test[J]. Journal of Hydraulic Engineering, 2002(6): 106-112. (in Chinese)) [10] 孙 红, 葛修润, 牛富俊, 等. 上海粉质黏土的三轴CT实时细观试验[J]. 岩石力学与工程学报, 2005, 24(24): 4559-4564 SUN Hong, GE Xiu-run, NIU Fu-jun,,et al. Real-time CT meso-testing on Shanghai silty clay subjected to triaxial loading[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(24): 4559-4564. (in Chinese)) [11] 吴紫汪, 马 巍, 蒲毅彬, 等. 冻土单轴蠕变过程中结构变化的CT动态监测[J]. 冰川冻土, 1996, 18(4): 306-311 WU Zi-wang, MA Wei, PU Yi-bin,,et al. Monitoring the change of structures in frozen soil in uniaxial creep process by CT[J]. Journal of Glaciology and Geocryology, 1996, 18(4): 306-311. (in Chinese)) [12] 马 巍, 吴紫汪, 蒲毅彬, 等. 冻土三轴蠕变过程结构变化的CT动态检测[J]. 冰川冻土, 1997, 19(1): 52-57 MA Wei, WU Zi-wang, PU Yi-bin,,et al. Monitoring the change of structures in frozen soil in triaxial creep process by CT[J]. Journal of Glaciology and Geocryology, 1997, 19(1): 52-57. (in Chinese)) [13] 赖远明, 吴紫汪, 朱元林, 等. 大阪山隧道围岩冻融损伤的CT分析[J]. 冰川冻土, 2000, 22(3): 206-210 LAI Yuan-ming, WU Zi-wang, ZHU Yuan-lin,,et al. CT analysis of frost damage of the surrounding rocks of a tunnel in the Daban mountain[J]. Journal of Glaciology and Geocryology, 2000, 22(3): 206-210. (in Chinese)) [14] 凌贤长, 徐学燕, 邱明国, 等. 冻结哈尔滨粉质黏土动三轴试验CT检测研究[J]. 岩石力学与工程学报, 2003, 22(8): 1244-1249 LING Xian-zhang, XU Xue-yan, QIU Ming-guo,,et al. Study on CT scanning of Harbin frozen silty clay. Before and after dynamic triaxial test [J]. Chinese Journal of Rock Mechanics and Engineering, 2003, 22(8): 1244-1249. (in Chinese)) [15] 孙星亮, 汪 稔, 胡明鉴. 冻土三轴剪切过程中细观损伤演化CT动态试验[J]. 岩土力学, 2005, 26(8): 1298-1311 SUN Xing-liang, WANG Ren, HU Ming-jian. A CT -timely experimental study on meso-scopic structural damage development of frozen soil under triaxial shearing[J]. Rock and Soil Mechanics, 2005, 26(8): 1298-1311. (in Chinese)) [16] 刘增利, 张小鹏, 李洪升. 基于动态CT识别的冻土单轴压缩损伤本构模型[J]. 岩土力学, 2005, 26(4): 543-546 LIU Zeng-li, ZHANG Xiao-peng, LI Hong-sheng. A damage constitutive model for frozen soils under uniaxial compression based on CT dynamic distinguishing[J]. Rock and Soil Mechanics, 2005, 26(4): 543-546. (in Chinese)) [17] 沈 为. 损伤力学[M]. 武汉: 华中理工大学出版社, 1995. SHEN Wei. Damage mechanics[M]. Wuhan: Huazhong University of Science and Technology Press, 1995. [18] LEMAITRE J. 损伤力学教程[M]. 倪金刚, 陶春虎, 译. 北京: 科学出版社, 1996 LEMAITRE J. A course on damage mechanics[M]. NI Jin-gang, TAO Chun-hu, translator. Beijing: SciencePress, 1996. (in Chinese)) [19] 张长庆, 苗天德, 王家澄, 等. 冻结黄土蠕变损伤的电镜分析[J]. 冰川冻土, 1995, 17(增刊1): 54-59 ZHANG Chang-qing, MIAO Tian-de, WANG Jia-cheng,,et al. An analysis on creep damage of frozen loess by electron-microscope[J]. Journal of Glaciology and Geocryology, 1995, 17(S1): 54-59. (in Chinese)) [20] 马 巍, 吴紫汪. 围压作用下冻结砂土微结构变化的电镜分析[J]. 冰川冻土, 1995, 17(2): 152-158 MA Wei, WU Zi-wang. Analysis of micro-structural changes in frozen sandy soil under confining pressure using scanning electronic microscope [J]. Journal of Glaciology and Geocryology, 1995, 17(2): 152-158. (in Chinese)) [21] 赵淑萍, 马 巍, 郑剑锋, 等. 不同温度条件下冻结兰州黄土单轴试验的CT实时动态监测[J]. 岩土力学, 2010, 31(增刊2): 92-97 ZHAO Shu-ping, MA Wei, ZHENG Jian-feng,,et al. CT real-time monitoring on frozen Lanzhou loess with different temperature under uniaxial loading[J]. Rock and Soil Mechanics, 2010, 31(S2): 92-97. (in Chinese))