Fig xA PGA and spectral accelerations for three vibration

Confidence Factor FC summarizes the knowledge level regarding the structure and the foundation system, from a geometric and mechanical point of view. It can be determined defining different partial confidence factors FCk (k = 1,4), on the basis of some numerical coefficients present in Italian Code (Table 4.1 Italian Guidelines). Due to the limited knowledge level achieved in this case, the highest confidence factor (FC = 1.35) was used.
After visual inspections, the values adopted for Triptolide and masonry elastic moduli are taken in agreement with Table C8A.2.1 of the Explicative Notes [24], assuming a masonry typology constituted by clay bricks (a so-called Ferraresi bricks typology is cortex present in all cases, with approximate dimensions equal to 300 × 60 × 100 mm3) with very poor mechanical properties of the joint and quite regular courses.
With the lowest knowledge level LC (confidence factor FC = 1.35), Italian Code requires to select, in Table C8A.2.1, the lower bound values for strength and the average values between lower and upper bound for elastic moduli.