Behaviour of the Borbone Constructive System Under Cyclic Loading: Preliminary Report

The Borbone constructive system, constituted by masonry reinforced with timber frames, was conceived in the Calabria region after the earthquake of 1783. In fact, subsequently to this catastrophic event Ferdinando of Borbone the IV immediately drew up an anti-seismic code in which prescribed, among the other rules, the buildings reconstruction to be carried out with the reinforcement of a skeleton of timber elements. Also the residence of the Bishop of Diocese of Mileto-Nicotera-Tropea was built in Mileto (Vv), at the end of 18th c., adopting the Borbone anti-seismic system. This “baracca” of the Bishop was investigated with an accurate dimensional and structural survey, supported by petrographic and chemical analysis of mortars and stones and by assessment of the wood species of the inner members of the load bearing system. All these data allowed the designers to realize an “imperfectly” identical copy of the bishop’s building wall. The paper will present the results of quasi-static cyclic tests according to UNI EN 12512:2003, on the full scale specimen of the Mileto masonry reinforced with timber framing. Furthermore, the hysteretic behaviour (ductility, energy dissipation, equivalent viscous damping ratio, strength impairment) of the Borbone constructive system will be discussed in the document, with a special focus on the single anti-seismic contribution of masonry and timber frame to the overall cyclic stiffness.