Post-earthquake seismic analysis of St James church, New Zealand

Abstract

The paper presents a numerical study of the seismic assessment of the St James Church in Christchurch, New Zealand affected by the most recent 2011 earthquake and subsequent aftershocks. Dynamic identification tests, as well as a careful visual inspection, were performed in the Church in order to understand its structural behaviour after the seismic action. The seismic assessment of the Church has been done using the finite element modelling technique, in which the nonlinear behaviour of masonry has been taken into account by proper constitutive assumptions. A model updating according to the experimental results was carried out in order to validate the numerical model, which includes the simulation of the damage identified in the structure. Nonlinear pushover analyses were carried out demonstrating that, as a result of the seismic action, the Church can no longer be considered safe. Another numerical model was analysed, this time considering the intact structure. The pushover analysis results of this undamaged model show good agreement with the visual inspection performed in situ, which further validates the model used. Moreover, since the analysis proved that the structure is no longer safe, a reinforcement strategy is proposed and analysed, proving its effectiveness.