web-based peer ground motion database

Web-Based PEER Ground Web-Based PEER Ground Motion Database Motion Database

Camila CoriaResearch AssistantPEER – UC Berkeley

PEER & NEES Annual Meeting, San Francisco October 8, 2010

Carola Di AlessandroPost–Doctoral FellowPEER – UC Berkeley

INTRODUCTIONINTRODUCTION

Based on DGML Application Interactive web application based on DGML

Ver. 2.0 software package

PEER & NEES Annual Meeting, San Francisco October 8, 2010

w/ thanks tow/ funding

from

PEER Ground Motion Database(http://peer2.berkeley.edu/peer_ground_motion_database) Shallow crustal earthquakes in active tectonic

regimes

SEARCH FORSEARCH FORGROUND MOTION RECORDSGROUND MOTION RECORDS

UNSCALED Records Based on earthquake parameters OR

PEER & NEES Annual Meeting, San Francisco October 8, 2010

Event name / NGA Sequence or Station Name

SEARCH FORSEARCH FORGROUND MOTION RECORDSGROUND MOTION RECORDS

SCALED Records

Need a TARGET SPECTRUM NGA Model User Defined Spectrum ASCE Code Spectrum

PEER & NEES Annual Meeting, San Francisco October 8, 2010

PEER – NGAPEER – NGATARGET SPECTRUMTARGET SPECTRUM

EPSILON: Number of Standard Deviations

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Input panel to create PEER-NGA Spectrum

CONDITIONAL MEAN: Option to apply the Conditional

Mean Method

PERIOD of CONDITIONAL MEAN Method: Specifies the period for the

Conditional Mean Method

PEER – NGAPEER – NGATARGET SPECTRUMTARGET SPECTRUM

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Conditional Mean Option “NO”Conditional Mean Option “NO”

EPSILON: Number of Standard Deviations

away from the median value

1st OPTION: Generate a constant Epsilon Spectrum

EpsilonEpsilon=0=0

Epsilon=Epsilon=11

Epsilon=Epsilon=22

(e.g. epsilon=1.0 for an 84th-percentile spectrum)

Examples of constant epsilon spectra generated using theaverage of five NGA modelsand epsilon = 0, 1, and 2

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Specify the value of Epsilon at a Spectral Period(Baker & Jayaram, 2008)

PEER - NGA PEER - NGA TARGET SPECTRUMTARGET SPECTRUM

Conditional Mean Option “YES”Conditional Mean Option “YES”

EpsilonEpsilon=0=0

EpsilonEpsilon=1 =1

Conditional Mean Spectrum, Epsilon=1, T_eps=0.5 sec

2nd OPTION: Develop a Conditional Mean Spectrum

(Baker & Cornell, 2006)

Example of a conditionalmean spectrum (CMS)created for an epsilon valueof 1.0 at a spectral periodof 0.5 seconds

SEARCH ENGINESEARCH ENGINE

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RECORD ACCEPTANCECRITERIA: Perform search over NGA

Database

WEIGHT FUNCTION: Specification of Weight

Function used for scaling

records

SEARCH ENGINESEARCH ENGINE

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RECORD ACCEPTANCECRITERIA:

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

Scaling options:

Seismological parameters

Unscaled MatchingUnscaled Matching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

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SCALING OPTIONS:

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

UnscaledUnscaledMatchingMatching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

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SCALING OPTIONS:

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

UnscaledUnscaledMatchingMatching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

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SCALING OPTIONS:

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

UnscaledUnscaledMatchingMatching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

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1) Scale the record to match the target spectrum to a single period:

the records are scaled to match the target spectrum at a specific spectral period, called Ts (sec)

)(

)(arg

srecord

sett

TSA

TSAf

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

Unscaled MatchingUnscaled Matching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

PEER & NEES Annual Meeting, San Francisco October 8, 2010

2) Scale the record to match the target spectrum over a period range:

the records are scaled by a factor that minimizes the mean squared error (MSE) between the geometric mean spectra of the scaled records horizontal components and the target spectrum

ii

i irecord

itarget

i

)w(T

)(TSA)(TSAln )w(T

fln

SCALINGSCALING

Period (sec)Period (sec)

Factor LimitFactor Limit

Unscaled MatchingUnscaled Matching

SingleSinglePeriodPeriod

NO

NO

YES

YES

SEARCH ENGINESEARCH ENGINE

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WEIGHT FUNCTION W(Ti):

Arbitrary values can emphasize match over narrow period range

i)

iw(T

i )i

(TrecordSA

)i

(TtargetSAln )

iw(T

fln A real number sequence

of periods and weights used to specify the weight function

SEARCH ENGINESEARCH ENGINE

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RANKING of MATCHING RECORDS :

Ranking is a function of weight function

MATCHINGMATCHINGRECORDSRECORDS

INCREASINGMSE

INCREASINGBEST MATCHING

PEER GROUND MOTION DATABASEPEER GROUND MOTION DATABASE

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Additional videos will be soon posted

INFORMATIONINFORMATION

Link:

http://peer2.berkeley.edu/peer_ground_motion_database

E-mail:

peer_center@berkeley.edu

PEER & NEES Annual Meeting, San Francisco October 8, 2010