Modeling of wetting deformation of coarse saline soil with an improved von Wolffersdorff model
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ORIGINAL PAPER
Modeling of wetting deformation of coarse saline soil with an improved von Wolffersdorff model Songhe Wang 1
&
Jian Xu 2,3
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Qinze Wang 1
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Dongxing Cheng 4
Received: 26 October 2019 / Accepted: 20 May 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Assessment of wetting-induced deformation of coarse saline soil is required to facilitate the settlement control of infrastructures such as the transmission lines in Northwest China. The coarse saline soil exhibits high internal friction angle like common gravels and the cohesion up to 34.6 kPa, as revealed by direct shear tests. Laboratory wetting tests indicate that significant deformation occurs after water immersion, and the higher the water content, the lower the wetting deformation (or the lower the wetting collapsibility coefficient), and the shorter it takes to reach the deformation stability standard (0.01 mm/h). An improved von Wolffersdorff model and water-solute coupled transport model were used to simulate the settlement of coarse saline soil foundation during field immersion test. The effective wetting range (Sr > 60%) rapidly expands in coarse saline soil layer after water immersion, from bulb-shaped wetting front to disc-shaped, like the profiles of pore water pressure. Solute moves synchronously with water, primarily in the mode of convective diffusion. Compared with the limited horizontal deformation, settlement of foundation mainly occurs in the vertical direction, and increases with stepwise load. Keywords Coarse saline soil . Wetting deformation . Water migration . Hypoplasticity . Solute transport
Introduction Saline soil is often treated as a problematic soil when used as the foundation of infrastructures (Mandal et al. 2008; Chikhaoui et al. 2015), and three types of engineering problems are seriously concerned by scholars and engineers, i.e., salt heaving (Darrow et al. 2009; Shaygan et al. 2018), chemical corrosion (He et al. 2020), and wetting collapse (Moayed et al. 2012). Compared with the former two types, the wetting-induced collapse of foundation attracts more attention, especially in the coarse saline soil in Northwest * Jian Xu [email protected] 1
State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, Shaanxi, China
2
School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, Shaanxi, China
3
Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, Shaanxi, China
4
Northwest Electric Power Design Institute Co., Ltd. Of China Power Engineering Consulting Group, Xi’an 710075, Shaanxi, China
China, which is classified as arid and semi-arid area with high evaporation but low precipitation concentrated in rainy season (Xu et al. 2019). However, the coarse saline soil is often treated as common gravels when designing the foundation of infrastructures such the transmission lines. The wetting deformation is neglected
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