mpm- · pdf filempm-dredge piap-ga-2012-324522 landslides (source: geocaching.com, 2013)...
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MPM-DREDGEPIAP-GA-2012-324522
Welcome
Kenichi Soga
MPM-DREDGE
PIAP-GA-2012-324522
Dumping of geocontainers in water
Model test of the dumping of geocontainers (Deltares)
MPM simulation (source: Więckowski, 2013)
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MPM-DREDGE
PIAP-GA-2012-324522
cross-section
Submarine slides
(source: De Jager, 2008)
natural and man-made erosion and liquefaction
Dredge Sludge DepotHollandsch Diep 2007
Eastern Scheldt Barrier 2013
distance [m]
dept
h[m
m-N
AP]
(source: Deltares, 2014)
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MPM-DREDGE
PIAP-GA-2012-324522
Landslides
(source: geocaching.com, 2013)
(Tyrol Austria, 14 May 2013)
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MPM-DREDGE
PIAP-GA-2012-324522
Failure of levees
internal erosion
piping
overtopping
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MPM-DREDGE
PIAP-GA-2012-324522
Dredging activities
• stability of dredging processes• liquefaction and breaching• soil erosion, sedimentation and scour
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MPM-DREDGE
PIAP-GA-2012-324522
Erosion and scour
coastal erosion scour under pipelines
Holderness coast, Yorkshire
Beach houses, Netherlands
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Basic FEM approaches as basis of MPM
- mesh deforms as the bodydeforms
- material does not cross elements- nodes remain on boundary- mesh distortion?
- material flows througha fixed mesh
- no mesh distortion- state parameters in history
dependent materials?
Lagrangian : mesh deforms as the body deforms à “SOIL MECHANICS”
Eulerian : material flows through a fixed mesh à “FLUID MECHANICS”
Basis of MPM
Lagrangian Eulerian
initial configuration deformation after resetting the mesh
in each calculation step :
Material Point Method (MPM)Conservation of momentum
Conservation of mass
Use computational grid
Map MP info tonodes
Solve equilibriumequations
Map accelerationfield to MPs
Update positionand info of MPs
Background mesh & material pointsCollapsing sand column
initial position ofmaterial points
final position ofmaterial points
material pointsmove through
fixed mesh
Collapsing sand column
total displacements [m]total displacements [m]
NOR-SAND - LOOSE SAND
no numerical damping
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NOR-SAND - DENSE SAND
loos
ede
nse
MO
HR
-CO
ULO
MB
loos
ede
nse
NO
R-S
AND
MPM Coupled Consolidation formulation
MPM Coupled Consolidation formulation
Modelling Partially saturated soil
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• Model large deformations
Properties
E 10 MPa
ϕ 30.8º
C’u 2.0 kPa
ψpeak -5.0º
γpeak 0.01
γf 0.2
su (suction) 2.7 kPa
n (porosity) 0.45
μ (boundary) 0.3
k (permeability) 5×10-4
m/s
Kw (bulk modulus) 1×109 Pa
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MPM-DREDGE
PIAP-GA-2012-324522
Program
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MPM-DREDGE
PIAP-GA-2012-324522
Speakers
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