Paolo Morandi1, Carlo F. Manzini2, Emanuele Bossi1, and Guido Magenes1
1) Department of Civil Engineering and Architecture (DICAr), University of Pavia
Via Ferrata 3, 27100 Pavia, Italy
e-mail:{paolo.morandi, emanuele.bossi, guido.magenes}@unipv.it
2) European Centre for Training and Research in Earthquake Engineering (EUCENTRE)
Via Ferrata 1, 27100 Pavia, Italy
carlo.manzini@eucentre.it
Keywords: Modern masonry buildings, Seismic performance, Design with Eurocodes, Emilia
2012 earthquake, Elastic analysis, Pushover analysis.
Abstract. The seismic performance of three modern unreinforced masonry buildings struck by the earthquake sequence of May 2012 in Emilia (Italy) has been investigated, to define the safety margins and the possible critical issues in the seismic design according to the European seismic codes. The selected structures have been redesigned, applying linear and static non-linear analyses, and verified against collapse, according to both Eurocodes 6 and 8 and Italian Norms for Constructions. The use of the “ϕ method”, proposed by Eurocode 6 for compression/flexure mechanisms, has provided inconsistent results, where none of the three buildings fulfilled the safety checks even at very low lateral action, although two of the structures did not attain any visible damage after the events of May 2012, whereas with the use of the flexural strength criterion included in the Italian seismic code the safety checks have provided, at least for static non-linear analyses, results much more in line with the actual seismic response of the buildings. The main issue of the elastic analyses, which has instead produced very conservative results, stays in the definition of the seismic action (and, in particular, of the behaviour factor q), and it could be solved only through a rational evaluation of an effective method for the redistribution of the forces.