Seismic assessment of the historical third tower in San Marino based on a 3D laser scanner survey (3D-LSS)

Italian recent earthquakes demonstrated that historic and monumental buildings are extremely vulnerable to seismic motions. In particular, masonry towers are particularly affected by horizontal loads because of their typological features (slenderness and base shear area). In this regard, San Marino historical center was object of an extended case study to assess the seismic assessment of the monuments. This paper presents a seismic assessment of the historic third tower in San Marino based on several subsequent steps: a preliminary 3D laser scanner survey, a modal frequency identification and a final pushover analysis. The evaluation of the vulnerability of the tower is fundamental for decision makers in order to provide guidelines and establish priority of intervention among historic monuments. In particular, Level 1 and Level 3 were chosen as the approaches under which the structural parameters were calibrated. Following EC8, N2 method was applied in order to assess the vulnerability of the tower.