Report - PEER - University of California, Berkeley

A EUROPEAN PERSPECTIVE TO PERFORMANCE-BASED SEISMICDESIGN, ASSESSMENT AND RETROFITTINGMichael N. FARDIS 1ABSTRACTPerformance-based features of the recent first European Standard for seismic design ofbuildings (EN1998-1:2004) and of the final draft European Standard for seismic assessmentand retrofitting of buildings (prEN1998-3, May 2004) are reviewed, with emphasis on concretebuildings. EN1998-1:2004 includes two performance levels: (a) local collapse endangeringlives and (b) limitation of damage in structural and non-structural elements. They are meant tobe checked under a rare and an occasional earthquake, respectively, with the definition of theassociated seismic hazard levels left to the country. Buildings designed for energy dissipationare protected from global collapse under a very rare (but unspecified) earthquake across-theboardapplication of capacity design to control the inelastic mechanism. The link between thebehavior factor q that reduces elastic lateral forces of the (local-) collapse preventionearthquake and member detailing against member collapse is derived. prEN1998-3 provides for3 performance levels: near collapse, significant damage and limited damage. The country willdecide which ones will be checked and may leave the associated hazard level to be chosen byowners. Verification of ductile members is fully deformation-based. The tools for verificationof existing, new or retrofitted members are given as expressions for their limit deformations.Keywords: Earthquake-resistant design; Eurocode 8; Performance-based seismic design;Seismic assessment; Seismic design; Seismic retrofitting.1. PERFORMANCE-BASED DESIGN IN EC8 AND ITS BACKGROUNDSince the early 90’s, the activity of the European Earthquake Engineering communityhas been centered around, and motivated by, the drive towards European codification,namely the development of a European Standard for seismic design: Eurocode 8, or“EN1998: Design of structures for earthquake resistance”. Recent fruits of this effortare the two parts of Eurocode 8 positively voted in March 2004 (CEN 2004a):• EN1998-1:2004, “Part 1: General rules, seismic actions, rules for buildings”,• EN1998-5:2004, “Part 5: Foundations, retaining structures, geotechnicalaspects”and the very recent draft (CEN 2004b):• prEN1998-3, “Part 3: Assessment and retrofitting of buildings,”1 Department of Civil Engineering, University of Patras, GR26500, Greece, fardis@upatras.gr1