Seismic Vulnerability Reduction of Masonry Churches: A case study

Abstract

This paper presents some advanced FE analyses conducted on a masonry church damaged by the recent Emilia earthquake, occurred on 20th-29th May 2012. The Nativity of the Virgin Mary parish, located in the province of Ferrara (Italy), was subjected to a post-earthquake strengthening intervention, which consisted of introducing steel profiles, rigid diaphragms and repointing technique for the damaged masonry material. The earthquake highlighted a series of pre-existing structural vulnerabilities. A probable mechanism involving the detachment of the façade was also observed due to the presence of vertical cracks. Three FE models were created in order to investigate the seismic behavior of the church in the original, retrofitted and proposed FRP-retrofitted configurations. The mechanical properties of the material were adapted from National Technical Code recommendations for existing masonry constructions by introducing a macro-scaling homogenization technique. The performed numerical analyses highlighted the seismic vulnerability of the church in the original and retrofitted configurations. A strengthening intervention performed by means of FRP strips was numerically investigated. The results obtained by using the three different FE models were compared and the use of FRPs was found to be a quite reasonable strengthening intervention, ensuring a considerable seismic upgrading.