Numerical survey, analysis and assessment of past interventions on historical timber structures: the roof of Valentino Castle

The paper analyzes a series of reinforcement interventions performed on the historical timber roof structure of the Valentino Castle in Torino (Italy) some thirty years ago. It is not very common to be able to assess the durability of interventions without relying to accelerated ageing test. In this case a real structure is considered, which was consolidated by one of the authors (C. Bertolini) in the past. Recently the laser scanning survey has strengthened a relevant interest in sectors as monitoring and static assessment of building structures. The high detailed models which is possible to reach, and the chance to foresee the accuracy and the resolution of surface models, make them particularly adaptable for studies concerning conservation and maintenance of cultural heritage. The laser survey models is compared with the documentation of the intervention fulfilled three decades ago, in order to evidence the general safety level of whole complex. The fully three-dimensional geometrical information is input in the finite element code, and a structural model is presented which is able to account for the positive contribution of the roof planking connected above the main truss frame. Both the original planking and the reinforcing planking, put in place some thirty years ago, have been accounted for, considering different degrees of the connection stiffness. The paper, starting from the original design, presents an assessment of the durability of the adopted techniques according to the present situation. The effectiveness of the past interventions is proved by nowadays survey, NDT investigations and numerical simulations.