PSI - Issue 29

Michele Paradiso et al. / Procedia Structural Integrity 29 (2020) 87–94 Michele Paradiso, Sara Garuglieri and Viola Ferrarini / Structural Integrity Procedia 00 (2019) 000 – 000

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Using graphic sta tics, the kinematic chain of the sequentialmechanism that leads to deformation of the arch, with its consequent collapse, was studied. To this end, thehypothetical initia l geometry of the archwas reconstructedbased on the measurements carried out on site. The results extracted f rom the Strauss 7 software were compared with the direct measurement, and in this way the rotationhinges were identifiedwithin the geometry of the arch. It was therefore hypothesized that even in the original conformation thesepoints had the function of hingesand the act of motion for infinitesimal rigid displacements of the three trucks highlighted was studied to understand if the results were qualitatively comparable to today's real situation: the reasoningmade trough thekinematic chain is in line with the kinematics of rigid infinitesimal displacement which studies the trend of movement and therefore a llows us to conclude that the investigations made so far do not contradict reality (Figure 4.b). As a last investigation technique, a 1/3 scale model was created to carry out real tests on the types of subsidence and horizontal displacement. The arch and the support were made of lightweight concrete blocks, cut following the origina l shape of the arch in a ll its segments and calculated for their weight according to a direct proportionality between their real weight and that of the model blocks. The test involved a combination of vertical settlements and horizontal translations: thefirst hinge to openwas the one between the5/6ashlar, a t the same time the hinges opened between the8/9and 9/10 segments (thesecond largest) and the downwardmovement of thesegments 4/5/6begin. In the last pre-collapse phase, there was the openingof an additional hinge between the 2/3 segments (Figure 4.c). On a qualitative level, the results obtainedby thevarious approachesarecompatible with each other andcompatible with the current situation. The obtained results confirmed that thereasonof thefailure lies in the co -existence of static and dynamic actionsand, a bovea ll, of important seabed subsidencedue to thescars presence of foundations, the poor dra inage systemof ra inwater, a deep risinghumidity, the presence of large parts of landand the lack ofmaintenance [Pugi (2013); Ga lassi (2019); Tempesta (2019)].

Fig. 4. Garuglieri S., Ferrarini V., Comparison between the finals results: (a) Numerical model by Straus7; (b) kinetostatic analysis, static graphics; (c) Experimental model 2. Hypothesis forstructural consolidation As previously mentioned, the entire complex has undergone significant a ltera tions tha t have irreversibly compromised its authenticity, conservation and structural stability. Having regard to the particular loca l situation, ra ther thanopting for a recognizable restorationproject a lso linked to the use of innovative materials and techniques for the reintegra tion in many cases necessary, a conservative approach was chosen with the use of originalmaterials and construction techniques to demonstrate the possibility of constructive continuity; in this section, a descriptionof the proposed intervention concerning the roofs, arches and foundations is briefly reported. Thanks to the studyof the roof portions preserveduntil 2015, built with the typical characteristics of Cubancolonial architecture [Weiss (1978)], it was propose to replace those thatwere severely damaged, absent or partially collapsed with new wooden roofs and floors of similar characteristics. The proposed display was intended not to represent a stylistic imita tion, bu t a simple reproduction of a construction method, structurally efficient and “compatible” to the context. Particular a ttention was paid to the design and the reinforcement of the points of contact between the wall