Abstract：Gaomiaozi (GMZ) Ca-bentonite has obvious swelling and shrinkage characteristics. The change in suction can induce changes in water retention state and void ratio. Soil-water characteristics of GMZ Ca-bentonite at high suctions (3～287 MPa) are measured by the vapor equilibrium technique. The influential factors such as drying-wetting process, initial void ratio, stress loading history and pore structure are analyzed respectively on the soil-water characteristics and mechanical behaviour. The main conclusions are as follows: (1) the difference in void ratio during drying and wetting process can bring about hysteresis in volumetric water content and degree of saturation; (2) the relationship between degree of saturation and suction is mainly determined by the pore structure and void ratio, which has no direct relation with the experienced stress loading history; (3) the soil-water characteristic curve (SWCC) can reflect the deformation characteristics with suction. Moreover, the existence of suction in samples can produce suction stress. The suction stress increases nonlinearly with the increasing suction and reaches a certain value at higher suction; (4) the suction stress due to suction is affected by the factors such as suction path, initial void ratio and pore structure.
孙文静, 孙德安, 刘仕卿, 方雷. 高吸力下高庙子钙基膨润土的土水-力学特性[J]. 岩土工程学报, 2014, 36(2): 346-353.
SUN Wen-jing, SUN De-an, LIU Shi-qing, FANG Lei. Hydro-mechanical behaviour of GMZ Ca-bentonite at high suctions. Chinese J. Geot. Eng., 2014, 36(2): 346-353.
[1] 刘月妙, 温志坚. 用于高放射性废物深地质处置的粘土材料研究[J]. 矿物岩石, 2003, 23(4): 42-45. (LIU Yue-miao, WEN Zhi-jian. Study on clay-based materials for the repository of high level radioactive waste[J]. J Mineral Petrol, 2003, 23(4): 42-45. (in Chinese)) [2] LLORET A, VILLAR M V. Advances on the knowledge of the thermo-hydro-mechanical behaviour of heavily compacted “FEBEX” bentonite[J]. Physics and Chemistry of the Earth, 2007, 32(8/9/10/11/12/13/14): 701-715. [3] ROMERO E, GENS A, LLORET A. Water permeability, water retention and microstructure of unsaturated compacted Boom clay[J]. Engineering Geology, 1999, 54(1/2): 117-127. [4] IMBERT C, OLCHITIZKY E, LASSABATERE T, et al. Evaluation of a thermal criterion for an engineered barrier system[J]. Engineering Geology, 2005, 81(3): 269-283. [5] TANG A M, CUI Y J. Controlling suction by the vapour equilibrium technique at different temperatures and its application in determining the water retention properties of MX80 clay[J]. Canadian Geotechnical Journal, 2005, 42(1): 287-296. [6] CHEN Bao, QIAN Li-xin, YE Wei-min, et al. Soil-water characteristic curves of Gaomiaozi bentonite[J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(4): 788-793. [7] YE Wei-min, WAN Min, CHEN Bao, et al. Effect of temperature on soil-water characteristics and hysteresis of compacted Gaomiaozi bentonite[J]. J Cent South Univ Technol, 2009, 16(5): 821-826. [8] 张虎元, 张 明, 崔素丽, 等. 混合型缓冲回填材料土水特征曲线测试与修正[J]. 岩石力学与工程学报, 2011, 30(2): 382-390. (ZHANG Hu-yuan, ZHANG Ming, CUI Su-li, et al. Determination and modification of soil-water characteristic curves of bentonite-sand mixtures as high-level waste backfill/buffer material[J]. Chinese Journal of Rock Mechanics and Engineering. 2011, 30(2): 382-390. (in Chinese)) [9] 孟德林, 孙德安, 刘月妙. 高庙子膨润土与砂混合物的土-水特征曲线[J]. 岩土力学, 2012, 33(2): 509-514. (MENG De-lin, SUN De-an, LIU Yue-miao. Soil-water characteristic curves of Gaomiaozi bentonite-sand mixtures[J]. Rock and Soil Mechanics, 2012, 33(2): 509-514. (in Chinese)) [10] 秦 冰, 陈正汉, 孙发鑫, 等. 高吸力下持水曲线的温度效应及其吸附热力学模型[J]. 岩土工程学报, 2012, 32(10): 1877-1886. (QIN Bing, CHEN Zheng-han, SUN Fa-xin, et al. Temperature effect on water retention curve under high suction and its modeling based on thermodynamics of sorption[J]. Chinese Journal of Geotechnical Engineering, 2012, 32(10): 1877-1886. (in Chinese)) [11] 缪林昌, 刘松玉. 南阳膨胀土的水分特征和强度特性研究[J]. 水利学报, 2002, 33(7): 87-92. (MIAO Lin-chang, LIU Song-yu. Soil-water characteristics and shear strength of expansive soil [J]. Journal of Hydraulic Engineering, 2002, 33(7): 87-92. (in Chinese)) [12] 白福青, 刘斯宏, 袁 骄. 滤纸法测定南阳中膨胀土土水特征曲线试验研究[J]. 岩土工程学报, 2011, 36(6): 928-933. (BAI Fu-qing, LIU Si-hong, YUAN Jiao. Measurement of SWCC of Nanyang expansive soil using the filter paper method[J]. Chinese Journal of Geotechnical Engineering, 2011, 36(6): 928-933. (in Chinese)) [13] 唐朝生, 施 斌. 干湿循环过程中膨胀土的胀缩变形特征[J]. 岩土工程学报, 2011, 33(9): 1376-1384. (TANG Chao-sheng, SHI Bin. Swelling and shrinkage behaviour of expansive soil during wetting-drying cycles[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(9): 1376-1384. (in Chinese)) [14] 吴礼舟, 黄润秋. 膨胀土开挖边坡吸力和饱和度的研究[J].岩土工程学报, 2005, 27(8): 970-973. (WU Li-zhou, HUANG Run-qiu. Study on suction and saturation of excavated expansive soil slope[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(8): 970-973. (in Chinese)) [15] 李志清, 胡瑞林, 王立朝, 等. 非饱和膨胀土SWCC研究[J]. 岩土力学, 2006, 27(5): 730-734. (LI Zhi-qing, HU Rui-lin, WANG Li-chao, et al. Study on SWCC of unsaturated expansive soil[J]. Rock and Soil Mechanics, 2006, 27(5): 730-734. (in Chinese)) [16] 龚壁卫, 吴宏伟, 王 斌. 应力状态对膨胀土SWCC的影响研究[J]. 岩土力学, 2004, 25 (12): 1915-1918. (GONG Bi-wei, CHARLES W W Ng, WANG Bin. Influence of stress states on soil-water characteristics of expansive soils[J]. Rock and Soil Mechanics, 2004, 25 (12): 1915-1918. (in Chinese)) [17] ZHAN Liang-tong, CHEN Ping, NG C W W. Effect of suction change on water content and total volume of an expansive clay[J]. Journal of Zhejiang University, Science A, 2007, 8(5): 699-706. [18] 孔令伟, 李雄威, 郭爱国, 等. 脱湿速率影响下的膨胀土工程性状与持水特征初探[J]. 岩土工程学报, 2009, 31(3): 335-340. (KONG Ling-wei, LI Xiong-wei, GUO Ai-guo, et al. Preliminary study on engineering behaviors and water retention characteristics of expansive soil under influence of drying rate[J]. Chinese Journal of Geotechnical Engineering, 2009, 31(3): 335-340. (in Chinese)) [19] GB 50112—2013 膨胀土地区建筑技术规范[S]. 北京: 中国计划出版社, 2013. (GB 50112—2013 Technical code for buildings in expansive soil regions[S]. Beijing: China Planning Press, 2013. (in Chinese)) [20] The International Organization of Legal Metrology (OIML). The scale of relative humidity (RH) of air certified against saturated salt solutions[S]. OIMLR 121, 1996. [21] 殷宗泽, 袁俊平, 韦 杰, 等. 论裂隙对膨胀土边坡稳定的影响[J]. 岩土工程学报, 2012, 34(12): 2155-2161. (YIN Zong-ze, YUAN Jun-ping, WEI Jie, et al. Influences of fissures on slope stability of expansive soil[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(12): 2155-2161. [22] LIN B, CERATO A B. Hysteretic soil water characteristics and cyclic swell-shrink paths of compacted expansive soils[J]. Bull Eng Geol Environ, 2013, 72(1): 61-70. [23] ALONSO E E, VAUNAT J, GENS A. Modelling the mechanical behaviour of expansive clays[J]. Engineering Geology, 1999, 54(1/2): 173-183. [24] FRELUND D G, XING A Q. Equations for Soil-water characteristic curve [J]. Canadian Geotechnical Journal, 1994, 31(4): 521-532. [25] VANAPALLI S K, FREDLUND D G, PUFAHL D E. The influence of soil structure and stress history on the soil-water characteristics of compacted till[J]. Geotechnical Testing Journal, 1999, 19(3): 259-268. [26] SUN D A, SHENG D C, SLOAN S W. Elastoplastic modeling of hydraulic and stress-strain behavior of unsaturated soils[J]. Mechanics of Materials, 2007, 39(3): 212-221. [27] KARUBE D, KAWAI K. The role of pore water in the mechanical behaviour of unsaturated soils[J]. Geotechnical and Geological Engineering, 2001, 19(3/4): 211-41. [28] SUN D A, MATSUOKA H, YAO Y P, et al. An elastoplastic model for unsaturated soil in three-dimensional stresses[J]. Soils and Foundations, 2000, 40(3): 17-28. [29] 龚壁卫, 周小文, 周武华. 干-湿循环过程中吸力与强度关系研究[J]. 岩土工程学报, 2006, 28(2): 207-209. (GONG Bi-wei, ZHOU Xiao-wen, ZHOU Wu-hua. Test on suction and strength of expansive soil in a desorption-absorption cycle of moisture[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(2): 207-209. (in Chinese)) [30] 赵成刚, 李 舰, 刘 艳, 等. 非饱和土力学中几个基本问题的探讨[J]. 岩土力学, 2013, 34(7): 1825-1831. (ZHAO Cheng-gang, LI Jian, LIU Yan, et al. Discussion on some fundamental problems in unsaturated soil mechanics[J]. Rock and Soil Mechanics, 2013, 34(7): 1825-1831. (in Chinese)) [31] 孙德安. 土水特征影响因素的试验研究[C]// 土工测试新技术——第25届全国土工测试学术研讨会论文集. 杭州: 浙江大学出版社, 2008: 211-215. (SUN De-an. Experimental study on influential factors of soil-water characteristics[C]// Proceedings of the 25th National Symposium on Geotechnical Testing. Hangzhou, 2008: 211-215. (in Chinese))
