Modeling and Simulations for Geotechnical Problems
Modeling and Simulations for GeotechnicalProblems
Boris Jeremic
Department of Civil and Environmental EngineeringUniversity of California, Davis
http://sokocalo.engr.ucdavis.edu/ ˜jeremic/
JHU Workshop, November 2005,
Modeling and Simulations for Geotechnical Problems
Overview of Features
Systems Approach
I Elasticity (small and large deformation, linear, nonlinear,isotropic, cross anisotropic...)
I Elasto–plasticity (small and large deformations, isotropic,anisotropic, deterministic, stochastic
I Solid elements (small and large deformations)I Single and multi–phase formulations (u–p–U for small def.,
u–p for large def.)I Parallel computations using Plastic Domain Decomposition
MethodI Seismic analysis using Domain Reduction Method (with
above features)
Modeling and Simulations for Geotechnical Problems
Stochastic Elasto-Plasticity
Low OCR Cam Clay withRandom G, M and p0
0.1
0.2
0.3
00.010.020.030.040
200
400
Stress (MPa)
0
Time (s)
Strain (%)
0
1.62
ProbDensity
0
200
400
0 0.05 0.1 0.15 0.2 0.25 0.3
0
0.01
0.02
0.03
0.04
Time (s)
Strain (%)0 1.62
Std. Deviation Lines
Mean LineDeterministic Line
Mode Line
Stre
ss (M
Pa)
50
30
10
Modeling and Simulations for Geotechnical Problems
Stochastic Elasto-Plasticity
High OCR Cam Clay withRandom G and M
0.1
0.2
0.3
00.010.020
200
400
Stress (MPa)
Time (s)
Strain (%)
0
2
0
ProbDensity
0.37
0
200
400
0 0.05 0.1 0.15 0.2 0.25 0.3 0.37
0
0.005
0.01
0.015
0.02
0.025
0.03
Strain (%)
Mean Line
Std. Deviation Lines
Time (s)
0 2.0
Stre
ss (M
Pa)
3050
100
Deterministic LineMode Line
Modeling and Simulations for Geotechnical Problems
Soil–Foundation–Structure Interaction
Beneficial orDetrimental?
5 10 15 20−10
−5
0
5
10
Time [s]
Mom
ent [
MN
m]
Structure 1Fixed BaseSFSImax/min(Fixed Base)max/min(SFSI)
0
2
4
6
8
Nat
ural
Fre
quen
cy [H
z]
5 10 15 20−4
−2
0
2
4
Time [s]
Mom
ent [
MN
m]
Structure 2 Fixed BaseSFSImax/min(Fixed Base)max/min(SFSI)
0
4
8
12
16
Nat
ural
Fre
quen
cy [H
z]
5 10 15 20−3
−2
−1
0
1
2
3
Time [s]
Mom
ent [
MN
m]
Structure 3 Fixed BaseSFSImax/min(Fixed Base)max/min(SFSI)
0
2.5
5
7.5
10
12.5
15
Nat
ural
Fre
quen
cy [H
z]
5 10 15 20−10
−5
0
5
10
Time [s]
Mom
ent [
MN
m]
Structure 4Fixed BaseSFSImax/min(Fixed Base)max/min(SFSI)
0
4
8
12
16
Nat
ural
Fre
quen
cy [H
z]
I NEHRP–94 seismiccode states thatommiting SFSI ison safe side
I Reality andsimulations showdifferent picture
Modeling and Simulations for Geotechnical Problems
Conclusions
There are many parts to succesfull simulations forgeotechanical and structural problems
I Systems approach to model building (discovery),simulations, and results interpretation
I Education , practice and research : need to overcomeempirical (historical) approach
I Great oportunity and challenge to advance modern(good!) methodology to practice
I Economic forces (not cheaper but better design) andlitigation threat can actually help!
Modeling and Simulations for Geotechnical Problems
Invitation to WCCM
Consider submitting an abstract to the WorldCongress on Computational Mechanics, L.A. ’06
I Computational GeomechanicsI Organized by:
I Stein StureI Fusao OkaI Ronaldo BorjaI Richard RegueiroI Boris Jeremic
I Follow link from my web site to WCCM