Abstract:
Displacement-based design (DBD) is emerging as the new trend for seismic design of buildings. Several displacement-based design procedures have been developed in recent times. The performances of buildings designed using these methods are usually evaluated by conducting non-linear time history analysis (NLTHA). The efficiency of performance assessment depends on proper non-linear material modelling, selection of proper earthquake records and their scaling and appropriate setting up of limit states (acceptance criteria). The present paper discusses the provisions in various seismic guidelines including ATC 63, FEMA P695 (2009) and PEER Centre report No.2010/05 and recent research findings regarding the above parameters. According to FEMA P695, only the far-field record set is required for collapse assessment as there are many unresolved issues concerning the characterization of near-fault hazard and ground motion effects. To verify this, the response spectra are plotted for 10 selected far-field and near-field ground motions and found that there is considerable increase in the response of long period structures when they are subjected to near-field pulses. Time history analysis done on a 15-storeyed frame (which is designed as per DBD) shows an increase in roof displacement of the order of two and inter-storey drift amplification of about 2.7 near the base, when near-field ground motions are used for performance assessment.
