Consolidation in spatially random unsaturated soils based on coupled flow‐deformation simulation |
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| Authors: | Y Cheng LL Zhang JH Li LM Zhang JH Wang DY Wang |
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| Institution: | 1. State Key Laboratory of Ocean Engineering, Collaborative Innovation Center for Advanced Ship and Deep‐Sea Exploration, Department of Civil Engineering, Shanghai Jiaotong University, Shanghai, China;2. State Key Laboratory of Ocean Engineering, Civil Engineering Department, Shanghai Jiaotong University, Shanghai, China;3. Department of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, China;4. Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong;5. State Key Laboratory of Ocean Engineering, Shanghai Jiaotong University, Shanghai, China;6. Department of Geotechnical Engineering, Southwest Jiaotong University, Chengdu, China |
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| Abstract: | This paper integrates random field simulation of soil spatial variability with numerical modeling of coupled flow and deformation to investigate consolidation in spatially random unsaturated soil. The spatial variability of soil properties is simulated using the covariance matrix decomposition method. The random soil properties are imported into an interactive multiphysics software COMSOL to solve the governing partial differential equations. The effects of the spatial variability of Young's modulus and saturated permeability together with unsaturated hydraulic parameters on the dissipation of excess pore water pressure and settlement are investigated using an example of consolidation in a saturated‐unsaturated soil column because of loading. It is found that the surface settlement and the pore water pressure profile during the process of consolidation are significantly affected by the spatially varying Young's modulus. The mean value of the settlement of the spatially random soil is more than 100% greater than that of the deterministic case, and the surface settlement is subject to large uncertainty, which implies that consolidation settlement is difficult to predict accurately based on the conventional deterministic approach. The uncertainty of the settlement increases with the scale of fluctuation because of the averaging effect of spatial variability. The effects of spatial variability of saturated permeability ksat and air entry parameters are much less significant than that of elastic modulus. The spatial variability of air entry value parameters affects the uncertainties of settlement and excess pore pressure mostly in the unsaturated zone. Copyright © 2016 John Wiley & Sons, Ltd. |
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| Keywords: | unsaturated soil hydro‐mechanical coupling consolidation spatial variability random field Monte Carlo simulation |
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