Report - PEER - University of California, Berkeley

ASSESSMENT OF SEISMIC PERFORMANCE IN TERMS OFECONOMIC LOSSESEduardo MIRANDA 1 , Hesameddin ASLANI 2 and Shahram TAGHAVI 2ABSTRACTAn approach for describing the seismic performance of buildings as a continuum and in termsof economic losses is presented. Two alternative measures of economic losses are describedand discussed. In the proposed approach the total loss in a building due to physical damage istreated as a random variable and it is computed as the sum of the losses in individual structuraland nonstructural components. Economic losses are computed using a fully probabilisticapproach that permits the explicit incorporation of uncertainties in the seismic hazard at thesite, in the response of the structure, on the fragility of individual structural and nonstructuralcomponents, and on the costs associated with the repairs or replacement of individual buildingcomponents. Physical damage is estimated by combining structural response parameters suchas interstory drift ratio or peak floor acceleration with component fragility functions. Resultsfrom an existing non-ductile seven story reinforced concrete building are presented to illustratethe proposed loss estimation methodology.Keywords: Performance-based seismic design; Probabilistic loss estimation; Fragilityfunction; Correlation; Loss deaggregation.1. INTRODUCTIONThe goal of performance-based seismic design (PBSD) is to design facilities thatsatisfy the performance expectations of their owners. Implicit in PBSD when appliedto buildings is the need to predict the performance of the structure, its non-structuralcomponents and contents for a wide range of possible earthquake ground motionintensities.Recent research conducted at the Pacific Earthquake Engineering Research(PEER) Center aims at describing the seismic performance of structures quantitativelyby continuous variables rather than discrete performance levels such as those used inFEMA 356 document. The three continuous variables studied by PEER include:economic (e.g., dollar) losses, downtime and fatalities. The present work is focusedon economic loss estimation.1 Assistant Professor, Dept. Civil and Envir. Engrg., Stanford University, Stanford, CA, 94305-40202 Ph.D. Student, Dept. Civil and Envir. Engrg., Stanford University, Stanford, CA, 94305-4020149