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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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

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Landslides

(source: geocaching.com, 2013)

(Tyrol Austria, 14 May 2013)

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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

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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

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Program

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MPM-DREDGE

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Speakers

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