Vulnerability Assessment of Unreinforced Masonry Churches Following the 2010–2011 Canterbury Earthquake Sequence

Abstract

The 2010–2011 Canterbury, New Zealand earthquake sequence caused extensive damage to unreinforced masonry churches. A sample of 80 affected buildings was analysed and their performance statistically interpreted. Structural behaviour is described in terms of mechanisms affecting the so-called macro-elements, and damage probability matrices are computed. Regression models correlating mean damage level against macroseismic intensity are also developed for all observed mechanisms, improving the initial simple-linear formulations through use of multiple-linear regressions accounting for vulnerability modifiers, whose influence is evaluated via statistical procedures. Results presented herein will support the future development of predictive tools for decision-makers, also contributing to seismic vulnerability mitigation at a territorial scale.