PSI - Issue 78

Alberto Lemme et al. / Procedia Structural Integrity 78 (2026) 293–300

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4. Numerical modelling and verification at the artistic limit state For Palazzo Ardinghelli, some verifications were carried out at the SLA (artistic limit state) introduced by the Directive of the Council of Ministers of 9 February 2011 and the assessment was carried out with local models on parts of the building considered to be of value or in any case for which an assessment of the level of acceleration induced by a potential earthquake is expected. The following are some elaborations on two decorative stone decorations: the loggia on the courtyard, for which the numerical verification refers to the SLU (ultimate limit state), which in this specific case can coincide with the SLA as an element with a structural function, and the cornice. 4.1. The loggia The first calculation model was developed to estimate the acceleration leading to the damage. The model consists of beam elements, representing the pillars, and four-node shell elements used for the schematisation of the masonry. In Fig. 9(a) is the evaluation of the stresses induced in the masonry (shell elements) by the static loads, own weight plus the share of accidentals: the recorded vertical stress varies from 0 (red areas) to 0.75 MPa (purple areas). Fig. 9 (b) shows the state of the stresses induced in the masonry (shell elements) by static and seismic loads (at SLV): The recorded 'shear' stress varies from 0 (red) to 0.7 MPa (purple). (a) (b)

Fig. 9. Model of the loggia of Palazzo Ardinghelli in L'Aquila.

4.2. The cornice On the basis of the survey made and the reading of the type of damage to the cornice, in the simplified model a flexural failure of the "corbel" indicated by the red line in Fig. 10 is hypothesised due to the stresses of the overlying mass of masonry and the roof delimited by the blue vertical line. The yellow and green arrows indicate the actions due to gravitational loads G and horizontal seismic actions S. In Fig. 10 (a) there is a graphic sectional restitution of the cornice in the section between two successive volutes. The vertical blue line delimits the volume of the masonry and the overlying roof that rests on the 'corbelled' cornice indicated by the red line. The area filled in with the dotted line is masonry, that with the continuous oblique line sandstone. Fig. 10 (b) relates the stressing ag acceleration and the stress induced at the most stressed flap in the cornice. (a) (b)

0.4

0.3

0.2

0.1

0

0 2  10 5 4  10 5 6  10 5 8  10 5 1  10 6 1.2  10 6 1.4  10 6 0.1

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Fig. 10. Model of the cornice of Palazzo Ardinghelli in L'Aquila.