SEISMIC PERFORMANCE OF THE LOMBARD MASONRY BUTTRESS SYSTEMS

A brick masonry construction system developed in Lombardy region in the 12^th and 13^thcenturies, with heavy ribbed quadripartite vaults, often supported on double-system piers. These features—brick masonry construction, quadripartite domical vaults, and heavy solid buttresses are the characteristics of Lombard Romanesque architecture. A previous study investigated the proportions of the solid trapezoidal Lombard buttresses characteristic of this system which feature a particular connection wall built over the aisle vaults and extended to the ground outside the aisle walls. This study deepens into the performance of the structural system for lateral actions through a limit analysis model. The spread of this construction typology in relation to seismic is examined as well, also in relation to the possibility that the system was exported to Tuscany and adapted to the needs of later gothic works. One case study is here analysed: Chiaravalle abbey church, one of the main Milanese heritage buildings.