Working Group #2 – Tsunami Loading of Bridges

Members: Michael Scott (Lead-F), Ian Buckle (A), Ian Robertson(A), Marc Eberhard (A), Michael Motley (A), Gary Chock (A), SteveMahin (A), Jun-ichi Hoshikuma (A), Harry Yeh (A), Solomon Yim(A), Tom Murphy (F)F = Funded, A = volunteer Advisor (travel funded to extent possible)

Major Deliverables

1 Literature review of existing methods to estimate loads ofbridges along with supporting experimental data

2 Testing and/or modeling to fill in knowledge gaps

3 Determination of loading estimation approach

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 1 / 43

Summary of 2014 OSU Tsunami Modeling

Workshop

Michael H. Scott

Tsunami Bridge Design Specifications

Working Group #2 Meeting

July 21, 2016M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 2 / 43

Overview of Workshop

December 10-12, 2014, Corvallis, OR

Collaboration between PEER, PWRI, and UJNR

33 participants from US and Japan

Compare and discuss simulation methods, identify knowledge gaps

https://secure.engr.oregonstate.edu/wiki/tsunamiworkshop/index.php

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 3 / 43

Experimental Setup

1:20 scale bridge superstructure

30 m by 1 m flume

Gate release to initiate tsunami bore

Bridge Deck

WaveGauges

Gate

Pier

hSWL

hres

12.0 m

30.0 m

7.5 m

2.5 m

1.0 m

0.1 m0.25 m

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 4 / 43

Case 1

Slab bridge deck (5 m width, 1 m height)

SWL at bottom of slab (no clearance)

Expected flow height 2 m above top of deck

5 cm

25 cm

1.25 cm 1.25 cm15 cm

(expected

hSWL=20 cm

wave height forhres=51.8 cm)

20 cm

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 5 / 43

Case 2

Deck-girder bridge (10 m width, 2 m height, 1 m overhang)

2 m clearance over SWL

Expected flow height at top of deck

hSWL=10 cm

50 cm

20 cm

wave height for(expected

20 cm

hres=61.7 cm)5 cm 10.67 cm

2 cm 7 cm

3 cm

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 6 / 43

Case 3

Deck-girder bridge (same as Case 2)

1 m clearance over SWL (different from Case 2)

Expected flow height at top of deck (same as Case 2)

50 cm

20 cm

wave height for(expected

5 cm 10.67 cm2 cm 7 cm

3 cm

hSWL=15 cm

15 cm

hres=51.8 cm)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 7 / 43

Case 4

Deck-girder bridge (same as Case 2)

2 m clearance over SWL (same as Case 2)

Expected flow height at top of deck (same as Case 2)

Protective fairing to divert wave impact on bridge

50 cm

20 cm

10.67 cm2 cm 7 cm

3 cm

5 cm

hSWL=10 cm

hres=61.7 cm)wave height for

(expected

20 cm

5 cm

2.5 cm

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 8 / 43

Simulated Response Quantities

Force time histories

Total horizontal force, FH =∑FHi

Total vertical force, FV =∑FV i

Results shown here for Cases 2 and 3 (only differ by SWL)

FH

FH1 FH2 FH3

FV

FV 1 FV 2 FV 3 FV 4

FH4

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 9 / 43

Simulation Approaches

Volume of Fluid (VOF), Finite Element Method (FEM), andSmoothed Particle Hydrodynamics (SPH) formulations

Single-phase and two-phase flow assumptions in 2D and 3D

Various turbulence models

Name Numerical Formulation Turbulence Model Number of Dimensions Type of Phase Model

CADMAS-SURF VOF k-ε 2D Two-PhaseFS3M Multiple (coupled) LES 3D Two-Phase

OpenFOAM VOF k-ε Both 2D & 3D Two-PhaseOpenSees PFEM FEM N/A 2D Single Phase

Material Point Method (MPM) FEM N/A 2D Single PhaseStabilized FEM FEM Implicit LES 2D Two-Phase

GPUSPH SPH Sub-Particle Scale (SPS) 3D Single PhaseLS-DYNA FEM LES 3D Two-Phase

STAR-CCM+CFD VOF k-ε 3D Two-Phase

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 10 / 43

Material Point Method (MPM)

The MPM is anextension ofparticle-in-cellmethods tosolid mechanics

It combinesaspects ofmesh-free andgrid-basedapproaches

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.MPM

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 11 / 43

STAR-CCM

STAR-CCMuses RANS fluidformulation

3D two-phaseflow

SIMPLEalgorithm withdefault settings

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.STAR-CCM

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 12 / 43

LS-DYNA Implicit CFD

Navier-Stokesfluidformulation,FEM

LES turbulencemodel

Data for Case 3not archived

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.LS-DYNA

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 13 / 43

FS3M

Navier-Stokesfluidformulation,two-phase, VOF

LES turbulencemodel

FSI based onimmersedboundarymethod

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.FS3M

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 14 / 43

CADMAS-SURF

VOFformulation,two-phase

k-ε turbulencemodel

2D simulations

10 15 20 25 30

0

1,000

2,000

3,000

Total

Horizon

talForce(kN)

Case 2

Exp.CADMAS-SURF

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce

(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 15 / 43

OpenFOAM – I

VOFformulation,two-phase

2D and 3Dsimulations

Variousturbulencemodels(convergent in3D)

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.OpenFOAM

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 16 / 43

OpenFOAM – II

VOFformulation,two-phase

2D and 3Dsimulations

Laminar andturbulent flows

10 15 20 25 30

0

1,000

2,000

3,000

Total

HorizontalForce(kN)

Case 2

Exp.OpenFOAM

10 15 20 25 30

0

1,000

2,000

3,000Case 3

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Time (s)

TotalVerticalForce(kN)

10 15 20 25 30−2,000

0

2,000

4,000

Time (s)

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 17 / 43

Mean and Variance of Horizontal Force Simulations

Simulationmean capturesCase 2, butmisses impactforce measuredin Case 3

High simulationCOV for Case 2impact

10 15 20 25 30

0

1,000

2,000

3,000

Total

Horizon

talForce

(kN)

Case 2

Exp.Mean

10 15 20 25 30

0

1,000

2,000

3,000Case 3

Exp.Mean

10 15 20 25 300

0.5

1

1.5

Time (s)

COV

Horizon

talForce

COV

10 15 20 25 300

0.5

1

1.5

Time (s)

COV

Highly subjective, but insightful

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 18 / 43

Mean and Variance of Vertical Force Simulations

Simulationmean capturesCase 2 andCase 3

High simulationCOV for Case 2impact(spurious spikearound zeromean)

10 15 20 25 30−6,000

−4,000

−2,000

0

2,000

Total

VerticalForce

(kN)

Case 2

Exp.Mean

10 15 20 25 30−2,000

0

2,000

4,000Case 3

Exp.Mean

10 15 20 25 300

1

2

3

Time (s)

COV

VerticalForce

COV

10 15 20 25 300

1

2

3

Time (s)

COV

Highly subjective, but insightful

M.H. Scott (OSU) 2014 Workshop Summary Working Group 2 19 / 43

Workshop Outcomes

3D models generally worth the additional computational effortcompared to 2D models

Capture localized air pockets and vortex sheddingEasily adapted for skewed bridge decks

Use of turbulence models better captures response to high speedsteady flows

Initial/boundary conditions important, particularly with respectto gate release

Variance of simulation resultsLow variance for steady hydrodynamic forceHigh variance for impact force

Analysis of Cases 1 and 4 forthcoming

DiscussionM.H. Scott (OSU) 2014 Workshop Summary Working Group 2 20 / 43