Geomechanics and Engineering

  • 제23권5호
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  • Pages.419-429
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  • 2020
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  • 2005-307X(pISSN)
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  • 2092-6219(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Influence of spatial variability on unsaturated hydraulic properties

  • Tan, Xiaohui (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Fei, Suozhu (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Shen, Mengfen (Zhejiang University of Technology) ;
  • Hou, Xiaoliang (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Ma, Haichun (School of Resources and Environmental Engineering, Hefei University of Technology)
  • 투고 : 2019.05.27
  • 심사 : 2020.11.18
  • 발행 : 2020.12.10
⟨ 이전 논문 다음 논문 ⟩

초록

To investigate the effect of spatial variability on hydraulic properties of unsaturated soils, a numerical model is set up which can simulate seepage process in an unsaturated heterogeneous soil. The unsaturated heterogeneous soil is composed of matrix sand embedded with a small proportion of clay for simulating the heterogeneity. Soil-water characteristic curve and unsaturated hydraulic conductivity curve of the unsaturated soil are expressed by Van Genuchten model. Hydraulic parameters of the matrix sand are considered as random fields. Different autocorrelation lengths (ACLs) of hydraulic parameter of the matrix sand and different proportions of clay are assumed to investigate the influence of spatial variability on the equivalent hydraulic properties of the heterogeneous soil. Four model sizes are used in the numerical experiments to investigate the influence of scale effects and to determine the sizes of representative volume element (RVE) in the numerical simulations. Through a number of Monte Carlo simulations of unsaturated seepage analysis, the means and the coefficients of variations (COVs) of the equivalent hydraulic parameters of the heterogeneous soil are calculated. Simulations show that the ACL and model size has little influence on the means of the equivalent hydraulic parameters, but they have a large influence on the COVs of the equivalent hydraulic parameters. The size of an RVE is mainly affected by the ACL and the proportion of heterogeneity. The influence of spatial variability on the hydraulic parameters of the heterogeneous unsaturated soil can be used as a guidance for geotechnical reliability analysis and design related to unsaturated soils.

키워드

과제정보

The financial supports from the National Natural Science Foundation, China (41572282, 41972278) are greatly appreciated and acknowledged.

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