Introduction Real ESSI Simulator Summary

The Real ESSI Simulator

Boris Jeremic

University of California, DavisLawrence Berkeley National Laboratory, Berkeley

U.S. DOE Natural Hazard Phenomena MeetingGermantown MD, October 2016

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Outline

Introduction

Real ESSI Simulator

Summary

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Outline

Introduction

Real ESSI Simulator

Summary

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Motivation

MotivationI Improving seismic modeling and simulation for nuclear

facilities

I Develop an expert numerical modeling and simulation tool

I Use of high (appropriate) fidelity numerical models toanalyze seismic behavior of nuclear facility soil structuresystems

I Accurately follow the flow of seismic energy in a soilstructure system

I The goal is to create methodology and numerical modelingand simulation tool that is used to predict and inform ratherthan (force) fit

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Motivation

Hypothesis

I Earthquake, Soil, Structure Interaction (nonlinear/inelastic),plays a major role in successes and failures

I Timing and spatial location of energy dissipationdetermines location and amount of damage

I Control and direct timing and spatial location of energydissipation, to optimize soil structure system for

I Safety andI Economy

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Motivation

High Fidelity Predictive Capabilities

I Verification provides evidence that the model is solvedcorrectly. Mathematics issue.

I Validation provides evidence that the correct model issolved. Physics issue.

I Prediction: use of computational model to foretell the stateof a physical system under consideration under conditionsfor which the computational model has not been validated.

I Prediction under uncertainty:I Modeling uncertaintyI Parametric uncertainty

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Motivation

Modeling Uncertainty: Simplified ModelsI Simplified modeling: Features (important ?) are neglected

(3D/6D ground motions, nonlinearities/inelasticity)I Modeling Uncertainty: unrealistic and unnecessary

modeling simplificationsI Modeling simplifications: justifiable iff higher level

sophistication model shows are features not important

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Motivation

Parametric Uncertainty: Material and LoadsI Significant uncertainty in material and loadsI Need to propagate uncertainty through simulation, to give

regulators and engineers information for design, licensing...

5 10 15 20 25 30 35

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You

ng’s

Mod

ulus

, E (

kPa)

E = (101.125*19.3) N 0.63

−10000 0 10000

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0.00004

0.00006

0.00008

Residual (w.r.t Mean) Young’s Modulus (kPa)N

orm

aliz

ed F

requ

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Transformation of SPT N-value: 1-D Young’s modulus, E (cf. Phoon and Kulhawy (1999B))

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Outline

Introduction

Real ESSI Simulator

Summary

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Real ESSI Simulator

Nonlinear/Inelastic, 3D, time domain, sequential and/or parallelfinite element program developed for Realistic modeling andsimulation of Earthquake Soil Structure Interaction (ESSI)problems for Nuclear Facilities (infrastructure objects).

Real ESSI Modelling and Simulation Process:

I Model Development: gmsh, gmESSII Model Simulation:

I Domain Specific Language (DSL) for inputI Real ESSI simulationI Output all (DoFs, σij , εij )

I Result Visualization: VisIt/visitESSI, and ParaView

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Real ESSI Program Features

I Finite Elements: solids (dry/single, coupled); truss; beams;shell; wall; plate; contact; base isolator/dissipator (all linearand/or nonlinear/inelastic)

I Material Models: Lin., nonlin, iso. and aniso. elastic;Elastic-Plastic (vMises, DrPr, R-MC, Leon-P, CClay,SSand, SClay, P); Damping, Rayleigh and Caughey

I Seismic input: the Domain Reduction Method (DRM,Bielak et al., analytic input of seismic motions)

I High Performance Computing: Parallel (Plastic DomainDecomposition Method), Template Metaprograms

I Probabilistic Modeling: (analytic) PEP and SEPFEM

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Nuclear Power Plants: 6D or 1D Seismic MotionsI Full 3D (6D) motions at the surface are recorded only in

one horizontal direction (1D)I From 1D recorded motions, develop a vertically

propagating shear wave in 1DI Apply full 3D and 1D seismic wave to SSI system

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Earthquake Motions

I Free field seismic motion modelsI Sources will send both P and S waves and produce

surface waves (see animations below)

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Earthquake Motions, 3D vs 1D

I Result of using one component of motions for 1D (from 3D)I Excellent (forced) fit in 1D, (see animations below)

I However it is not a prediction and information is lost

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

6D vs 1D NPP ESSI Response Comparison

(animations above)

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Elastic-Plastic Soil, Dense/Loose, Volume Change

I G/Gmax and damping datelacks volume change info

I Influences seismic motion

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max

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]

Seed & Idriss

frict, frict+visc

Seed & Idriss

frict

frict+viscous

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surf - no dilsurf - dil

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z = H/2

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τ [k

Pa]

γ [-]

z = H/2

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Contact ModelingI Soft (concrete to soil) and hard (concrete to rock/concrete)I Dry and Saturated contact (see animations below)

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Foundation – Soil/Rock SlipI Foundation slab slips significantly during an earthquakeI Base isolation (?!) and energy dissipationI Soil on sides restrict movementI Minimal gaping as contact sleeps before slab lifts-off

5 10 15 20 25 30Time [sec]

2.52.01.51.00.50.00.51.01.52.0

DX

[cm

]

Sliping of foundation

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Nonlinear vs Linear Response, Top of Containment

I Significant reduction of horizontal motionsI Reduction of vertical motions

2 4 6 8 10 12 14Frequency, f [Hz]

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SAX [g

]

With contactsLinear

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SAZ [g

]

With contactsLinear

horizontal vertical

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Seismic Energy Dissipation

(animations above)Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

Uncertain Material and Loads, Wave Propagation

5 10 15 20 25 30 35

5000

10000

15000

20000

25000

30000

SPT N Value

You

ng’s

Mod

ulus

, E (

kPa)

E = (101.125*19.3) N 0.63

−10000 0 10000

0.00002

0.00004

0.00006

0.00008

Residual (w.r.t Mean) Young’s Modulus (kPa)N

orm

aliz

ed F

requ

ency

I Probabilistic Elasto-PlasticityI Stochastic Elastic-Plastic FEM

0 0.0108 0.0216 0.0324 0.0432 0.0540

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0.0001

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Stre

ss (

MPa

)

Strain (%)

Mode

DeterministicSolutionStd. Deviations

Mean

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PDF

Displacement (mm)

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Displacement (mm)

PDF

Real Soil Data

Conservative Guess

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Real Soil DataConservative Guess

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bab

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xce

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0 c

m (

%)

Time (s)

Conservative Guess

Real Site

Characterized SiteExcellently

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Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

UNR Experimental Setup Modeling

I Detailed models of UNR test setup

I High level of sophistication to reduce modeling uncertainty

I Three models, progressively more sophisticated

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

UNR Experimental Setup, Model

I Hierarchy of models

I Used to gain better understanding of behavior (see animations below)

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Real ESSI Simulator

UNR Experiments, Design and ValidationI Detailed, parametric analysis

for the effects ofI Wall frictionI Soil inelastic responseI Cylinder rocking modesI Cylinder wobbling modes

I Models for validation of a freefield response

I Models for validation of SSI withattention to contact

I Models for high frequency wavetomography

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

Outline

Introduction

Real ESSI Simulator

Summary

Jeremic et al.

Real ESSI

Introduction Real ESSI Simulator Summary

SummaryI Goal: Reduction of modeling uncertainty for design and

assessment

I Goal: Enthuse professional practice and develop nextgeneration of experts in nonlinear ESSI

I Tool: Real ESSI Simulator System

I Education and training of users (designers, regulators,owners) will be the key to successful use of nonlinear ESSImodeling and simulation

I Collaborators: Yang, Preisig, Cheng, Jie, Sett, Taiebat,Tafazzoli, Karapiperis, Abell, Pisanò, Feng, Sinha, Lacour,Yang, Behbehani, Wang, Petrone, Wong, McKenna,McCallen

Jeremic et al.

Real ESSI