WebBased PEER Ground Motion Database Camila Coria Research
Web-Based PEER Ground Motion Database Camila Coria Research Assistant PEER – UC Berkeley Carola Di Alessandro Post–Doctoral Fellow PEER – UC Berkeley PEER & NEES Annual Meeting, San Francisco October 8, 2010
INTRODUCTION n PEER Ground Motion Database (http: //peer 2. berkeley. edu/peer_ground_motion_database) n n Shallow crustal earthquakes in active tectonic regimes Based on DGML Application n Interactive web application based on DGML Ver. 2. 0 software package w/ funding from PEER & NEES Annual Meeting, San Francisco w/ thanks to October 8, 2010
SEARCH FOR GROUND MOTION RECORDS n UNSCALED Records n Based on earthquake parameters OR n Event name / NGA Sequence or Station Name PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH FOR GROUND MOTION RECORDS n SCALED Records n Need a TARGET SPECTRUM n n n NGA Model User Defined Spectrum ASCE Code Spectrum PEER & NEES Annual Meeting, San Francisco October 8, 2010
PEER – NGA TARGET SPECTRUM n EPSILON: n n CONDITIONAL MEAN: n n Number of Standard Deviations Option to apply the Conditional Mean Method PERIOD of CONDITIONAL MEAN Method: n Specifies the period for the Conditional Mean Method Input panel to create PEER-NGA Spectrum PEER & NEES Annual Meeting, San Francisco October 8, 2010
PEER – NGA TARGET SPECTRUM n EPSILON: n Number of Standard Deviations away from the median value (e. g. epsilon=1. 0 for an 84 th-percentile spectrum) n 1 st OPTION: n Conditional Mean Option “NO” Generate a constant Epsilon Spectrum n Examples of constant epsilon spectra generated using the average of five NGA models and epsilon = 0, 1, and 2 PEER & NEES Annual Meeting, San Francisco Epsilon=2 Epsilon=0 October 8, 2010 Epsilon=1
PEER - NGA TARGET SPECTRUM n 2 nd OPTION: n Conditional Mean Option “YES” Develop a Conditional Mean Spectrum (Baker & Cornell, 2006) n Specify the value of Epsilon at a Spectral Period (Baker & Jayaram, 2008) Example of a conditional mean spectrum (CMS) created for an epsilon value of 1. 0 at a spectral period of 0. 5 seconds n PEER & NEES Annual Meeting, San Francisco Epsilon=1 Conditional Mean Spectrum, Epsilon=1, T_eps=0. 5 sec Epsilon=0 October 8, 2010
SEARCH ENGINE n RECORD ACCEPTANCE CRITERIA: n n Perform search over NGA Database WEIGHT FUNCTION: n Specification of Weight Function used for scaling records PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n RECORD ACCEPTANCE CRITERIA: n n Seismological parameters Scaling options: SCALING NO Unscaled Matching YES Single Period NO Factor Limit YES Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n SCALING OPTIONS: SCALING Unscaled Matching NO YES Single Period NO Factor Limit YES Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n SCALING OPTIONS: SCALING Unscaled Matching NO YES Single Period NO Factor Limit YES Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n SCALING OPTIONS: SCALING Unscaled Matching NO YES Single Period NO Factor Limit YES Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE 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) SCALING NO Unscaled Matching YES Single Period NO Factor Limit YES Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE SCALING NO Unscaled Matching 2) Scale the record to match the target spectrum over a period range: YES Single Period NO Factor Limit YES 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 Period (sec) PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n WEIGHT FUNCTION W(Ti): n A real number sequence of periods and weights used to specify the weight function n Arbitrary values can emphasize match over narrow period range PEER & NEES Annual Meeting, San Francisco October 8, 2010
SEARCH ENGINE n RANKING of MATCHING RECORDS : n Ranking is a function of weight function INCREASING BEST MATCHING RECORDS INCREASING MSE PEER & NEES Annual Meeting, San Francisco October 8, 2010
PEER GROUND MOTION DATABASE n Additional videos will be soon posted PEER & NEES Annual Meeting, San Francisco October 8, 2010
INFORMATION Link: http: //peer 2. berkeley. edu/peer_ ground_motion_database E-mail: peer_center@berkeley. edu PEER & NEES Annual Meeting, San Francisco October 8, 2010
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