PSI - Issue 78

Ciro Canditone et al. / Procedia Structural Integrity 78 (2026) 379–386

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palace body was accounted for by modelling return walls according to EC6 provisions (2005), that is, incorporating a flange length taken as the minimum between h w /5, l w /2 and 6 t w , with h w , l w and t w being, respectively, the wall height, length and thickness. This resulted in 20,202 elements, and hence a total of 121,212 DOFs due to 6 DOFs per rigid body. Hinged restraints were considered along the edge of such return walls to account for interlocking with the main Palace body. Vertical overburden and horizontal thrusts resulting from unmodelled vaults and floor systems were accounted for as distributed loads. Ultimately , perfect restraint conditions were assumed at model’s base to simulate the interaction with the underlying bedrock before the occurrence of foundation-level failure. Material properties were assumed based on values calibrated in (Sivori et al., 2023), complemented with values recommended by the Italian Building Code (D.M. 17.01.2018) and its Commentary (Circolare n°7, 21.01.2019).

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(b)

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Figure 2. (a) AEM model of Consoli Palace Loggia, (b) AEM model of internal vaults and (c) comparison between observed crack pattern and distribution of pre-cracked numerical interfaces.

4. Discussion of numerical analyses The AEM model was first subjected to self-weight and live loads, combined according to the accidental rule by Eurocode 1 (EC1, 2002), hence obtaining displacements and stresses associated with a fixed-base configuration. A comparison was also drawn with an undamaged model, whereby fixed-base stress and displacement states were not found to be influenced by the presence of pre-existing damage. Analysis of principal compressive stresses (Figure 3a) points to maximum stresses, approximately equal to 1 MPa, being observed (as expected) at foundation level, in the masonry pillars of L oggia’s façade, and at vault springing sections . Those stresses are approximately 1/6 th of masonry compressive strength, f c , set equal to 6.00 MPa according to values recommended in the Italian Building Code (D.M. 17.01.2018; Circolare n°7, 21.01.2019) for regularly coursed ashlar stone masonry. The structure is thus relatively safe with regards to ordinary gravity loads. With regards to displacements, maximum vertical (downward) and horizontal (out-of- plane, OOP) displacements, respectively equal to 5.5 mm and 3.0 mm, were observed at Loggia’s top colonnade. Façade OOP displacements are due to the horizontal thrusts produced by the barrel and cross vaults of Loggia’s floor system, as well as distributed loads accounting for the presence of a timber pitched roof. An analysis of total displacement contour (Figure 3b) points to the likely development of an overturning mechanism for the upper colonnade and corner, which is compatible with the observed crack pattern detailed in Figure 2c. As can be appreciated from Figure 3c, spring cracking due to tensile or shear failures can also be observed in the flange walls, in good agreement with displacement discontinuities. Such cracks are due to the combined action of pulling forces – associated