gmsv in seism project jonathan p. stewart university of california, los angeles

GMSV in SEISM Project

Jonathan P. StewartUniversity of California, Los Angeles

Outline

Possible areas of activity:• Geotechnical validation – duration sensitive– Not at top of list in validation gauntlet

• General validation / use of simulations– Fundamental to the validation gauntlet

Geotechnical Validation

• Site responseV s

InputRock Att.

G/GMax

D

g

Output

Equivalent-linear

Nonlinear

Geotechnical Validation

• Site response

Outcome:

Geotechnical Validation

• Site response• Nonlinear soil response

Element response:

Boulanger and Idriss, 2004

Fig. 23: Undrained Cyclic Simple Shear Test on Monterey #30/0 Sand (Test No. Ms15j)Dr=50%, v,i’=85 kPa, CSR=0.22 , =0

Fig. 24: Undrained Cyclic Simple Shear Test on Monterey #30/0 Sand (Test No. Ms30j)Dr=75%, v,i’=85 kPa, CSR=0.4 , =0

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.30 0.2 0.4 0.6 0.8 1

No

rm. S

hea

r S

tres

s, (

/ c )

Normalized Effective Vertical Stress, 'v/

c'

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3-10 -5 0 5 10

Shear Strain, (%)

0

5

10

15

20

25

30

35

00.20.40.60.81

Excess Pore Pressure Ratio, ru (%)

Nu

mbe

r o

f C

ycle

s

0

5

10

15

20

25

30

35

-10 -5 0 5 10

Shear Strain, (%)

-0.4

-0.2

0.0

0.2

0.4

0 0.2 0.4 0.6 0.8 1

No

rm. S

hear

Str

ess,

(/ c

)

Normalized Effective Vertical Stress, 'v/

c'

-0.4

-0.2

0.0

0.2

0.4

-10 -5 0 5 10

Shear Strain, (%)

0

5

10

15

20

25

30

00.20.40.60.81

Excess Pore Pressure Ratio, ru (%)

Nu

mbe

r o

f C

ycle

s

0

5

10

15

20

25

30

-10 -5 0 5 10

Shear Strain, (%)

Candidate metrics:

End of record pore pressure generation

Peak shear strain

Kammerer et al. (2002)

Candidate metrics:

End of record pore pressure generation

Peak shear strain

Post (or during) cyclic volume change

Yee et al. (2012).

Geotechnical Validation

• Site response• Nonlinear soil response• Newmark displacements

Newmark sliding block:

Geotechnical Validation

• Compute geotechnical engineering demand parameters (EDPs) of interest using recorded and simulated ground motion suites.

• OpenSees platform can be used

• Identify inconsistencies and their cause

General Validation / Use of Simulations

• Distance scaling; M-scaling• Spectral shape• Sigma from simulations (within- and between-

event)• Basin effects• Useful for: – Simulation validation– Constraining components of GMPEs poorly

constrained by data

Suggestion was to do geotechnical. My second suggestion is NGA-West3, so premature to do now.

Do it for the motions that pass the SWUS broadband validation project for the xx events. Select a series of simulated records and comparable real records and compare.

Some discussion of how do we compare apples and apples.

Could start by computing IMs for the sets that are relevant (CAV5, IA, duration, etc.). Could then compare sim/real for records with similar values of these Ims.

Coordinate with CG on this.