1. Modeling groundwater flow and piping
under dikes and dams
Groundwater flow simulator DgFlow

2. DgFlow simulator
Project history
• Flood control 1202195
• Knowledge for climate 1201351
• DSC mwell 1205933
• WTI piping 1206013, 1207809, 1209435
• WTI macro stability 1206015, 1207808, 1209434
• WTI overtopping waves 1206016, 1207811, 1209437
Project aims
• tool for safety assessment (ringtoets, dam)
• dGeoFlow (mseep, mwell, watex) next to dGeoStability
• research tool
17 juni 2014

3. 17 juni 2014
DgFlow simulator
Processes
• Saturated and unsaturated groundwater flow
• Deformation of the subsurface and engineered slopes
• Backward erosion piping
Loading
• Hydraulic loading by surface water
• Meteorological loading by precipitation and evaporation
• Overtopping waves

4. 17 juni 2014
DgFlow simulator
Implementation
• Quasi-static formulation, steady state / transient, 1,2,3D
• Finite element method, implicit time integration
• C++ kernel, C# interface, Paraview visualization

5. 17 juni 2014
DgFlow interface

6. 17 juni 2014
DgFlow simulation
Water level
variation
head
seepage
precipitation
submerging
uplift

7. 17 juni 2014
DgFlow simulation
Water level
variation +
overtopping
head
seepage
precipitation
submerging
uplift (heave)

8. Piping mechanism
17 juni 2014

9. Piping mechanism
17 juni 2014

10. Piping simulation
17 juni 2014

11. Piping validation
Lab experiment
17 juni 2014

12. Piping validation
Numerical experiment
17 juni 2014

13. Developments
2D assessment tool
• flow modeling and monitoring
• generalization of Sellmeijer’s rule
• multilayer systems
• complex geometries
• heterogeneous fields
• inclined layers
3D research tool
• innovative techniques
• field scale experiments
• laboratory experiments
17 juni 2014

14. Future developments
Assessment tool
• user interface
• mesh generator
• user manual
• verification
• validation
• benchmarks
• support
• link to dam and ringtoets
17 juni 2014

15. Research questions
Piping mechanism
• sensitivity to model parameters
• heterogeneity of permeability and grain size
• grain size distribution
• primary and secondary erosion
• single or multiple channels
• 3d effects micro scale
Groundwater flow
• validation in the field
• update Van Genuchten material model
17 juni 2014