Chapter Ten - Seismic Collapse Analysis of the CTV Building

Abstract

This chapter describes the investigation of the factors that caused the collapse of the Canterbury Television (CTV) building during the Lyttelton aftershock on February 22, 2011, in New Zealand. The building collapsed during the earthquake with the exception of the north-wall complex left standing. A numerical model of the building was constructed based on the actual structural drawing, and a static pushover analysis was conducted. The result showed its unbalanced strengths in the EW and NS directions because of a biased distribution of anti-seismic walls. Furthermore, the collapse behavior with a clear twist mode vibration around the north-wall complex was observed by carrying out a seismic collapse analysis. The period of the twist mode vibration at the southeast corner of the building coincidentally matched the predominant period of the seismic wave in EW direction, which might had led to the deterioration of the columns at the location.