Study on Water Characteristic Curve of Unsaturated Red Clay

DOI: https://doi.org/10.62517/jcte.202506204

Author(s)

Song Chen

Affiliation(s)

Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing, China

Abstract

Under the background of climate warming on the plateau regions, the freeze-thaw cycle has had a significant impact on issues such as slope stability. In this paper, three test methods were adopted to conduct soil-water characteristic curve tests on red clay in the southwest plateau region under various dry densities under freeze-thaw cycles. The fitting model of song was used to fit the test data to obtain the influence laws of freeze-thaw cycles and different dry densities on the suction force of soil samples, so as to provide a reference for engineering design. The test results show that the soil-water characteristic curves of red clay with different dry densities present a bimodal feature. Different dry densities and freeze-thaw cycles have a significant impact on the soil-water characteristic curves of red clay, and the influence is mainly concentrated in the low suction stage. The curves within the high suction force range almost coincide. The fitting degrees of the adopted fitting models were all >0.98, and the fitting was good.

Keywords

Red Clay; Freeze-Thaw Cycle; Direct Measurement Method; Shrinkage Characteristics; Fitting Mode

References

[1] DU Jun, LU Hongya, JIAN Jun. Variations of extreme air temperature events over Tibetfrom 1961 to 2010[J]. Acta Geographica Sinica, 2013, 68(09): 1269-1280. [2] Sun, D.A., Gao, Y., Zhou, A.N., Sheng, D.C., 2016. Soil–water retention curves and microstructures of undisturbed and compacted Guilin lateritic clay. Bull. Eng. Geol. Environ. 75, 781–791. [3] Baker R, Frydman S (2009) Unsaturated soil mechanics: critical review of physical foundations. Eng Geol 106(1-2):26–39. [4] Sun De'an, Gao You, Liu Wenjie, et al. Soil and water properties of red clay and its pore distribution [J]. Journal of Geotechnical Engineering, 2015,37(02):351-356. [5] CASINI F, VAUNAT J, ROMERO E, DESIDERI A. Consequences on water retention properties of double-porosity features in a compacted silt[J]. Acta Geotechnica, 2012, 7(2): 139-150. [6] 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. [7] QIAN J, LIN Z, SHI Z. Experimental and modeling study of water-retention behavior of fine-grained soils with dual-porosity structures[J]. Acta Geotechnica, 2022, 17(8): 3245-3258. [8] SUN D, YOU G, Annan Z, et al. Soil–water retention curves and microstructures of undisturbed and compacted Guilin lateritic clay[J]. Bulletin of Engineering Geology and the Environment, 2016, 75: 781-791. [9] DING L, HAN Z, ZOU W, et al. Characterizing hydro-mechanical behaviours of compacted subgrade soils considering effects of freeze-thaw cycles[J]. Transportation Geotechnics, 2020, 24: 100392. [10] Zhao Guitao, Han Zhong, Zou Weilie, et al. Effects of dry-wet and freeze-thaw cycles on soil-water and shrinkage characteristics of expansive soils [J]. Journal of Geotechnical Engineering, 2021,43(06):1139-1146. [11] DING L, VANAPALLI S K, ZOU W, et al. Freeze-thaw and wetting-drying effects on the hydromechanical behavior of a stabilized expansive soil[J]. Construction and Building Materials, 2021, 275: 122162. [12] Fredlund D G, Rahardjo H. Soil mechanics for unsaturated soils[M]. John Wiley and Sons, New York: New York, 1993. [13] YU Y, ZHANG Z, DAI F, et al. A New Shear Strength Model with Structural Damage for Red Clay in the Qinghai-Tibetan Plateau[J]. Applied Sciences, 2024, 14(8): 3169. [14] Wang Fei. Development of unsaturated soil column test device and study on capillary retardation type seepage prevention layer parameters [D]. Beijing: Beijing Jiaotong University, 2017. [15] GREESPAN L. Humidity fixed points of binary saturated aqueous solutions[J]. Journal of Research of the National Bureau of Standards, 1977, 81(1): 89–96.