Performances of FRP reinforcements on masonry buildings evaluated by fragility curves

The seismic vulnerability assessment of masonry buildings reinforced with FRP was investigated by means of random sampling of their mechanical properties and repeated nonlinear static analyses. To this aim, the Monte Carlo simulation method was adopted to account for the uncertainty of the mechanical parameters characterizing the analytical model representative of each structural prototype. In particular, a two-step procedure was proposed. First, to ensure an appropriate calibration of the model, was investigated the mechanical behavior of two case-studies structures: an unreinforced masonry panel and a masonry panel externally reinforced with FRP composite strips applied with a grid configuration and anchored properly at their ends. Then, the effectiveness of a FRP reinforcement designed for the main façade of the historical Camponeschi Palace (located in the city of L'Aquila, Italy) was estimated. The proposed methodology was used to determine the probability of occurrence of several damage states and to estimate the relevant probability density functions corresponding to different levels of ground motion. The novelties of the modeling procedure proposed, together with the benefits provided by the FRP reinforcement, were presented and discussed in detail.