The expansive soil canal in the Middle Route of South-to-North Water Transfer Project is easily subjected to the effect of freeze-thaw cycles. In order to investigate the influence of freeze-thaw cycles on soil-water characteristics of expansive soil, we measured the total suction and matric suction of Nanyang expansive soil subjected to different freeze-thaw cycles using the filter paper method, and fitted the relationship between matric suction, total suction and water content with Van Genuchten model and power function model, respectively. Results show that as the freeze-thaw cycle proceeds, the soil and water characteristic curves (SWCCs) of the matric suction and total suction shifted to the lower left side, with the air entry value and water holding capacity both declining. The osmotic suction decreased gradually with the increase of water content, but the osmotic suction at different freeze-thaw cycles did not vary significantly. Finally, the fitting models used in the paper are of high correlation coefficients and simple forms, and the parameters of the models tend to be stable as the number of freeze-thaw cycles increases.
Key words
expansive soil /
freeze-thaw cycles /
soil-water characteristics /
filter paper method /
total suction /
matric suction /
curve fitting
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1] 许雷,鲁洋,薛洋,等. 冻融循环下水泥改性膨胀土物理力学特性研究[J] .长江科学院院报,2017, 34(4):87-91,103.
[2] 徐丽丽,刘丽佳,徐昭巍,等. 季节冻土区膨胀土边坡冻害防护综合技术[J] .岩土工程学报,2016,38(增1):216-220.
[3] PUPPALA A J, PUNTHUTAECHA K, VANAPALLI S K. Soil Water Characteristic Curves of Stabilized Expansive Soils[J] .Journal of Geotechnical and Geoenvironmental Engineering, 2006, 132(6): 736-751.
[4] 边加敏. 石灰改良膨胀土的水稳定性研究[J] .长江科学院院报,2016, 33(1):77-82.
[5] 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, 33(6): 928-933.
[6] 孙德安,张俊然,吕海波.全吸力范围南阳膨胀土的土-水特征曲线[J] .岩土力学,2013,34(7):1839-1843.
[7] MIAO L C, LIU S Y, LAI Y M. Research of Soil Water Characteristics and Shear Strength Features of Nanyang Expansive Soil[J] .Engineering Geology, 2002, 65(4): 261-267.
[8] 周葆春,孔令伟. 考虑体积变化的非饱和膨胀土土水特征[J] .水利学报,2011, 42(10):1152-1160.
[9] 黄志全,岳康兴,李幻,等. 滤纸法测定非饱和膨胀土土水特征曲线试验[J] .南水北调与水利科技, 2015, 13(3): 482-486.
[10] GARDNER R. A Method of Measuring the Capillary Tension of Soil Moisture over a Wide Moisture Range[J] .Soil Science, 1937, 43(4): 277-284.
[11] NING L, LIKOS W J. Unsaturated Soil Mechanics[M] .New Jersey: Jhon Wiley & Sons Inc, 2004.
[12] SL 237—1999,土工试验规程[S] .北京: 中国水利水出版社,1999.
[13] 王钊,杨金鑫,况娟娟,等. 滤纸法在现场基质吸力量测中的应用[J] .岩土工程学报,2003,25(4):405-408.
[14] 河海大学.一种冻融冻胀模型试验装置及其试验方法:中国,CN201210425614.5[P] .2013-01-16.
[15] 许雷,薛洋,鲁洋,等. 不同冻结温度条件下膨胀土冻融循环试验[J] .水资源与水工程学报,2016, 27(5):189-193.
[16] 谭晓慧,余伟,沈梦芬,等. 土-水特征曲线的试验研究及曲线拟合[J] .岩土力学,2013,34(S2):51-56.
[17] SILLERS W S, FREDLUND D G, ZAKERZADEH N. Mathematical Attributes of Some Soil Water Characteristic Curve Models[J] .Geotechnical and Geological Engineering, 2001, 19(3/4): 243-283.
[18] 许雷,刘斯宏,鲁洋,等. 冻融循环下膨胀土物理力学特性研究[J] .岩土力学,2016,37(增2):167-174.
[19] WANG D, MA W, NIU Y,et al. Effects of Cyclic Freezing and Thawing on Mechanical Properties of Qinghai Tibet Clay[J] .Cold Regions Science and Technology, 2007, 48(1): 34-43.
[20] 许雷,鲁洋,宗佳敏,等. 冻融循环下南阳膨胀土直剪试验[J] .南水北调与水利科技,2015,13(5): 922-925.
[21] 马田田,韦昌富,陈盼,等. NaCl溶液对土体持水特性影响的试验研究[J] .岩土力学, 2015, 36(10): 2831-2836.