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Three‐dimensional hydromechanical modeling of internal erosion in dike‐on‐foundation
Author(s) -
Yang Jie,
Yin ZhenYu,
Laouafa Farid,
Hicher PierreYves
Publication year - 2020
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.3057
Subject(s) - internal erosion , geotechnical engineering , geology , finite element method , erosion , mechanics , dike , discrete element method , porosity , effective stress , foundation (evidence) , computer simulation , engineering , petrology , levee , structural engineering , geomorphology , physics , archaeology , history
Summary Currently, numerical studies at the real scale of an entire engineering structure considering internal erosion are still rare. This paper presents a three‐dimensional (3D) numerical simulation of the effects of internal erosion within a linear dike located on a foundation. A two‐dimensional (2D) finite element code has been extended to 3D in order to analyze the impact of internal erosion under more realistic hydromechanical conditions. The saturated soil has been considered as a mixture of four interacting constituents: soil skeleton, erodible fines, fluidized fine particles, and fluid. The detachment and transport of the fine particles have been modeled with a mass exchange model between the solid and the fluid phases. An elastoplastic constitutive model for sand‐silt mixtures has been developed to monitor the effect of the evolution of both the porosity and the fines content induced by internal erosion upon the behavior of the soil skeleton. An unsaturated flow condition has been implemented into this coupled hydromechanical model to describe more accurately the seepage within the dike and the foundation. A stabilized finite element method was used to eliminate spurious numerical oscillations in solving the convection‐dominated transport of fluidized particles. This numerical tool was then applied to a specific dike‐on‐foundation case subjected to internal erosion induced by a leakage located at the bottom of the foundation. Different failure modes were observed and analyzed for different boundary conditions, including the significant influence of the leakage cavity size and the elevation of the water level at the upstream and downstream sides of the dike.