Seismic Structural Assessment of the Christchurch Catholic Basilica, New Zealand

Abstract

An evaluation of the seismic performance of the Christchurch Catholic Basilica, New Zealand, also known as the Cathedral of the Blessed Sacrament, is presented. The cultural importance of the Basilica has been recognized, as it is listed as a Category I building on the New Zealand heritage register. Four strong earthquakes that occurred between September 2010 and June 2011 caused progressive damage and local collapse in the Basilica. Numerical analyses were performed to allow a seismic assessment of the Basilica using the Finite Element Method. A macro-modelling approach following homogenization concepts was considered and the seismic behaviour of the structure was evaluated through pushover analysis with the distribution of forces being proportional to the mass. The analyses allowed damage patterns and capacity curves to be determined, and identified the most vulnerable elements, the maximum load capacity, and the expected collapse mechanisms. Furthermore, a comparison between the numerical output and the existing crack patterns was undertaken, and good agreement was obtained. Finally, two strengthening techniques were evaluated with the aim of reducing the seismic vulnerability of the structure by avoiding collapse of the most vulnerable structural elements.

Effectiveness of seismic retrofitting of a historical masonry structure: Kütahya Kurşunlu Mosque, Turkey

“…As the adopted seismic retrofitting improves the global response of the structure by achieving the so-called box-behavior, in-plane failure mechanisms dominate the global response and, therefore, allow a better redistribution of the imposed stresses and failure to be controlled by in-plane shear mechanisms. Similar conclusions have already been noted in different studies performed on historical structures-for instance, in Karanikoloudis and Lourenço (2018), Ciocci, Sharma, and Lourenço (2018), and Silva, Mendes, Lourenço, and Ingham (2018). It is stressed that the adopted modeling approach is unable to capture disintegration of the masonry walls during seismic loading, meaning that the designer must decide on the adequacy of the masonry arrangement to prevent disintegration or take appropriate measures such as reinforced plasters to prevent this local phenomenon.…”

“…The masonry minaret was excluded since no structural damage was reported. As stated in Silva et al (2018), a three-dimensional numerical model composed of solid elements with fine meshing is preferable to represent such heritage structure with complex geometry. This strategy was adopted in several studies, namely Karanikoloudis and Lourenço (2018), Kazaz and Kocaman (2018), Kocaman et al (2018), Ciocci et al (2018), Valente and Milani (2018), and Almac et al (2016).…”

Nonlinear modeling of unreinforced masonry structures under seismic actions: validation using a building hit by the 2016 Central Italy earthquake

“…It is important to point out that no damage accumulation due to the series of earthquakes can be accounted for in the adopted numerical approach. A similar strategy was used in [27] for the seismic assessment of an historical masonry building that suffered a progressive damage due to a prolonged seismic sequence. For the X and Y directions of analysis, respectively, Figure 16 and Figure 17 present the damage patterns in terms of principal crack width obtained for values of horizontal load factor comparable to the PGA values recorded on August 24 th , 2016 and October 26 th , 2016 (see Table 1).…”

Pushover analysis of unreinforced irregular masonry buildings: Lessons from different modeling approaches

“…[1] Within this framework, it is important to define appropriate modeling strategies to perform nonlinear analysis of URM buildings under seismic actions. Advanced computational applications regarding the nonlinear behavior of masonry are commonly focused on the finite element method (FEM), such as [27][28][29][30][31][32], and, also, block-based models, in which the real masonry arrangement (units and mortar) is considered [33][34][35][36][37][38][39][40]. Such analyses require a high computational effort and are complex and expensive to be adopted in practical applications.…”