Journal of Yangtze River Scientific Research Institute ›› 2024, Vol. 41 ›› Issue (1): 143-150.DOI: 10.11988/ckyyb.20220826

• Rock-Soil Engineering • Previous Articles     Next Articles

Permeability and Soil-Water Characteristic Curve of Undisturbed Loess under Wetting-drying Cycles

CHANG Zhou1, YAN Chang-gen1, AN Ning2, LAN Heng-xing3,4, SHI Yu-ling3, BAO Han1, XU Jiang-bo1   

  1. 1. Highway School, Chang'an University,Xi'an 710064,China;
    2. Investment Management Company of China Construction Fifth Engineering Bureau,Changsha 410116,China;
    3. School of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China;
    4. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences,Beijing 100101,China
  • Received:2022-07-12 Revised:2022-11-15 Online:2024-01-01 Published:2024-01-15

Abstract: To assess the impact of wetting-drying cycles on the hydraulic properties of undisturbed loess, we performed saturated permeability tests and soil-water characteristic tests on Q3 loess from Gansu Province under four different wetting-drying cycle paths. The aim is to examine the changes in permeability and soil-water characteristic curves (SWCC) with the number of cycles, cycle amplitude, and lower bound water content. Results revealed that the deterioration of saturated permeability coefficients can be modeled using a hyperbolic function with respect to wetting-drying cycles. After six cycles, the deterioration tends to stabilize. As cycle amplitude increases, the deterioration of saturated permeability coefficients exhibits a linear increase, while a linear decrease with the rise in lower bound water content. The SWCC of loess can be represented by the V-G model; parameters θs, α, and n remain relatively unaffected, whereas the parameter θr declines exponentially with an increase in the number of cycles. Deterioration models for saturated permeability coefficients and SWCC models considering the above three parameters of wetting-drying cycles are established, enabling the prediction of unsaturated permeability coefficients of loess.

Key words: undisturbed loess, wetting-drying cycles, permeability coefficient, soil-water characteristic curve, deterioration model

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