Numerical Investigation of Four Seismic Upgrading Techniques on a Masonry Bell Tower: Fid-Bau Portal

Numerical Investigation of Four Seismic Upgrading Techniques on a Masonry Bell Tower

Milani, Gabriele / Shehu, Rafael / Valente, Marco

This paper presents some preliminary results from the numerical investigations of different interventions for the seismic upgrading of a masonry bell tower. Masonry bell towers belong to the cultural and historical heritage, are very widespread in Italy and their conservation has been given special attention in recent years. Their high vulnerability is related to the combination of mechanical material properties, geometrical irregularities, presence of inclination, foundation settlements and seismicity of the area. The present tower is located in Emilia Romagna Region, Northern Italy, recently stricken by a strong seismic sequence in May 2012. Analyses results show that the retrofitting of masonry bell towers is highly recommended in order to mitigate their present seismic risk. Four different upgrading techniques, consisting of grouted mortar, FRP sheets, internal steel frame and prestressing vertical rods, are investigated and compared in terms of structural performance improvement. The grouted mortar and internal steel frame techniques are found to be reasonable solutions when compared to the other proposals for the specific seismic intensity level. Furthermore, the other techniques have a relatively high level of invasiveness which is recommended to be avoid where possible. Experience has shown that the most effective interventions are those that not only protect the structure, but also preserve the built heritage.