TIME HAS NOT STOPPED... IN BUSSANA VECCHIA (ITALY)

Masonry buildings of historic interest represents the majority of the build heritage in Italy.
Their seismic vulnerability depends on several factors:

1) intrinsic and specific vulnerability of masonry materials;
2) structural vulnerability to horizontal earthquake forces;
3) vulnerability due to historical factors and building preservation.

Reduction of vulnerability is possible by applying retrofitting techniques.
My research thesis focused on the investigation of a masonry church in Bussana Vecchia (Imperia, Italy): Sant’Egidio Church.
The Department of Architectural Heritage and Landscapes, Liguria (Soprintendenza per i beni architettonici e paesaggistici) and the Municipality of Sanremo approved the project.

The investigation was led according to the Italian Guidelines for seismic risk assessment and reduction strategy and the Italian Technical Standards for Construction 2008 (“Linee Guida per la valutazione e riduzione del rischio sismico de patrimonio culturale” and “Norme tecniche per le costruzioni 14 gennaio 2008 – NTC 2008). The legislation establishes simplified methods and numerical analysis with technical support softwares to carry out the historic buildings seismic safety assessment and it divides the seismic vulnerability assessment into three levels increasing in accuracy.

The first step in the case study was the analysis of the historic construction (Sant’Egidio Church).
LV1 assessment led to the identification of the seismic safety index (indice di sicurezza sismica Is,sl), which allows to understand whether the building needs a rapid and immediate intervention or, if there is no imminent risk, more detailed analysis are needed.

The second step was LV3 assessment, carried out with ABAQUS software in order to examine the total/whole construction and identify the most vulnerable elements for retrofitting.
The case study was shaped three-dimensionally and the most vulnerable elements were investigated with the nonlinear dynamic finite element analysis. The next step was the project of a consolidation intervention to restore the box behaviour, lost with the collapse of the roof, and decrease the vulnerability level. A further nonlinear dynamic analysis checked the correctness of the project.

At the end, the research thesis shows the prospect of a covering for the Church, which allows the use of the interior space and protect decorations of stuccoes.