EXPERIMENTS ON THE SEISMIC PERFORMANCE OFHOLLOW-CORE FLOOR SYSTEMS IN PRECAST CONCRETEBUILDINGS

摘要

Recent earthquake engineering research undertaken at the University of Canterbury has aimed atdetermining whether New Zealand designed and built precast concrete structures, whichincorporate precast concrete hollow-core floor slabs, possess inadequate seating support details.A full scale precast concrete super-assemblage was constructed in the laboratory and tested intwo stages. The first stage investigated existing construction and demonstrated majorshortcomings in construction practice that would lead to very poor seismic performance. Thispaper presents the results from the second stage that investigates the efficiency of improvedconstruction details on seismic performance. The improved details consist of a simple (pinnedtype)connection system that uses a low friction bearing strip and compressible material for thesupporting beams together with a 750mm wide timber infill between the perimeter beams andthe first precast floor unit. Test results show a marked increase in performance between the newconnection detail and the existing standard construction details, with relatively small amounts ofdamage to both the frame and flooring system at high lateral drift levels. The results show thatinterstorey drifts in excess of 3.0% can be sustained without loss of support of the floor unitswith the improved detailing The overall performance of the super-assembly is determined interms of the hysteretic performance and the fragility implications in terms of the drift damage areclassified. Recommendations for future design and construction are made based on theperformance of the super-assemblage test specimen and a probabilistic fragility analysis.