Stabilisation of the Cathedral of the Blessed Sacrament following the Canterbury earthquakes

Seismic Structural Assessment of the Christchurch Catholic Basilica, New Zealand

“…The stones are linked through grout-filled cavities and have a thickness of about 50 cm. The internal and external claddings have a thickness of 12.5 cm of limestone [33].…”

“…The thickness of the concrete core is equal to 20 cm. The domes are copper lined and the main dome is supported by four large arches, made from no-fines concrete, that spring from four large piers at the first-floor level with an internal spiral above [33]. The main dome is located above the sanctuary, which is not a common feature of this type of church:…”

“…In order to assure an appropriate seismic behaviour, a structural study was performed in 2002, adopting simplified analyses and practical engineering judgement [33]. Based on this study, a strengthening intervention was carried out, which involved: (i) new reinforced concrete (RC) slabs with a thickness of 10 cm at the first-floor and roof levels, aiming at providing a box-behaviour with rigid diaphragms; (ii) steel ties with a diameter of 3.2 cm and RC ring-beams with a cross section of 20 × 60 cm 2 at the two bell towers, above and below the window openings; (iii) RC ring beams with sections of 20 × 60 cm 2 at the top of the main dome, above and below the windows; (iv) post-tensioning at alternate columns of the nave colonnade; (v) grouting of external parapets and ornaments;…”

Analysis of the Severe-Damage Online Felt Reports for the Canterbury (New Zealand) 2011 Aftershocks on 22 February Mw 6.2, 13 June Mw 6.0, and 23 December Mw 6.0

“…PGAs reached 2:2g in the Heathcote Valley, close to the epicenter, and up to 0:8g in the central business district (CBD), considerably exceeding the 2500-year design motions at some stations (Kaiser et al, 2012). More than 110 churches were damaged to some extent during the February event (Leite et al, 2013;Lester et al, 2013).…”

Constituent material properties of New Zealand unreinforced stone masonry buildings

“…The wall cross-section of these buildings is typically comprised of single or multi-leaf natural stone, with some cases (approximately 15-20%) of natural stone being used in conjunction with clay bricks or concrete [1,2]. Several public building, such as the Arts Centre and the Provincial Chambers in Christchurch, were constructed using load-bearing walls composed of a single clay brick internal leaf and multi-leaf natural stone [3], with a small number of buildings being constructed using a multi-leaf natural stone load-bearing wall with a cast insitu no-fines concrete core, such as the Cathedral of the Blessed Sacrament in Christchurch [4].…”