In order to provide information related to seismic vulnerability of non-ductile reinforced concrete (RC) frame buildings, and as a complementary investigation on innovative feasible retrofit solutions developed in the past six years at the University of Canterbury on pre-19170 reinforced concrete buildings, a frame building representative of older construction practice was tested on the shake table. The specimen, 1/2.5 scale, consists of two 3-storey 2-bay asymmetric frames in parallel, one interior and one exterior, jointed together by transverse beams and floor slabs. The as-built (benchmark) specimen was first tested under increasing ground motion amplitudes using records from Loma Prieta Earthquake (California, 1989) and suffered significant damage at the upper floor, most of it due to lap splices failure. As a consequence, in a second stage, the specimen was repaired and modified by removing the concrete in the lap splice region, welding the column longitudinal bars, replacing the removed concrete with structural mortar, and injecting cracks with epoxy resin. The modified as-built specimen was then tested using data recorded during Darfield (New Zealand, 2010) and Maule (Chile, 2010) Earthquakes, with whom the specimen showed remarkably different responses attributed to the main variation in frequency content and duration. In this contribution, the seismic performance of the three series of experiments are presented and compared.
The Christchurch region of New Zealand experienced a series of major earthquakes and aftershocks between September 2010 and June 2011 which caused severe damage to the city’s infrastructure. The performance of tilt-up precast concrete buildings was investigated and initial observations are presented here. In general, tilt-up buildings performed well during all three major earthquakes, with mostly only minor, repairable damage occurring. For the in-plane loading direction, both loadbearing and cladding panels behaved exceptionally well, with no significant damage or failure observed in panels and their connections. A limited number of connection failures occurred due to large out-of-plane panel inertia forces. In several buildings, the connections between the panel and the internal structural frame appeared to be the weakest link, lacking in both strength and ductility. This weakness in the out-of-plane load path should be prevented in future designs.
The timeliness and quality of recovery activities are impacted by the organisation and human resourcing of the physical works. This research addresses the suitability of different resourcing strategies on post-disaster demolition and debris management programmes. This qualitative analysis primarily draws on five international case studies including 2010 Canterbury earthquake, 2009 L’Aquila earthquake, 2009 Samoan Tsunami, 2009 Victorian Bushfires and 2005 Hurricane Katrina. The implementation strategies are divided into two categories: collectively and individually facilitated works. The impacts of the implementation strategies chosen are assessed for all disaster waste management activities including demolition, waste collection, transportation, treatment and waste disposal. The impacts assessed include: timeliness, completeness of projects; and environmental, economic and social impacts. Generally, the case studies demonstrate that detritus waste removal and debris from major repair work is managed at an individual property level. Debris collection, demolition and disposal are generally and most effectively carried out as a collective activity. However, implementation strategies are affected by contextual factors (such as funding and legal constraints) and the nature of the disaster waste (degree of hazardous waste, geographical spread of waste etc.) and need to be designed accordingly. Community involvement in recovery activities such as demolition and debris removal is shown to contribute positively to psychosocial recovery.
