Hierarchical multiscale numerical modelling of internal erosion with discrete and finite elements
- PDF / 3,143,188 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 34 Downloads / 179 Views
(0123456789().,-volV)(0123456789(). ,- volV)
RESEARCH PAPER
Hierarchical multiscale numerical modelling of internal erosion with discrete and finite elements Pouyan Pirnia1
•
François Duhaime1 • Yannic Ethier1 • Jean-Se´bastien Dube´1
Received: 16 May 2019 / Accepted: 17 June 2020 Ó Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract This paper presents a coupled finite and discrete-element model (FEM and DEM) to simulate internal erosion. The model is based on ICY, an interface between COMSOL, an FEM engine, and YADE, a DEM code. With this model, smaller DEM subdomains are generated to simulate particle displacements at the grain scale. Particles in these small subdomains are subjected to buoyancy, gravity, drag and contact forces for short time steps (0.1 s). The DEM subdomains provide the macroscale (continuum) model with a particle flux distribution. Through a mass conservation equation, the flux distribution allows changes in porosity, hydraulic conductivity and hydraulic gradient to be evaluated for the same time steps at a larger, continuum scale. The updated hydraulic gradients from the continuum model provide the DEM subdomains with updated hydrodynamic forces based on a coarse-grid method. The number of particles in the DEM subdomains is also updated based on the new porosity distribution. The hierarchical multiscale model (HMM) was validated with the simulation of suffusion. Results for the proposed HMM algorithm are consistent with results based on a DEM model incorporating the full sample and simulation duration. The proposed HMM algorithm could enable the modelling of internal erosion for soil volumes that are too large to be modelled with a single DEM subdomain. Keywords COMSOL Discrete element Finite element Internal erosion Suffusion YADE
1 Introduction Internal erosion can be defined as the seepage-induced erosion of soil particles through the pore network of a soil or through larger openings or conduits. It can result in serious damage for water-retaining structures such as embankment dams and levees [7]. Internal erosion includes four distinct mechanisms: regressive erosion, erosion along a concentrated leak, interfacial erosion, and suffusion. This & Pouyan Pirnia [email protected] Franc¸ois Duhaime [email protected] Yannic Ethier [email protected] Jean-Se´bastien Dube´ [email protected] 1
Laboratory for Geotechnical and Geoenvironmental Engineering (LG2), E´cole de technologie supe´rieure, 1100 Notre-Dame Ouest, Montreal, QC H3C 1K3, Canada
paper is centred on the numerical modelling of suffusion, the erosion of small particles through a coarser granular skeleton [13]. The design of a new dam does not normally require the numerical modelling of internal erosion as design criteria are available in the literature [13]. However, older waterretaining structures do not always satisfy these criteria. Dam safety studies could thus benefit from efficient methods for the numerical modelling of internal erosion. The methods that are cur
Data Loading...
