PSI - Issue 78

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

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2.3. Decoration applied to masonry having a significant mass that does not contribute to the strength of the structure. These elements can negatively influence the behaviour of the structure by increasing the vulnerability of certain mechanisms for high mass and weak connection to the structure (e.g. organs, large frames, large statues, ...). Such apparatuses can be both inside and outside buildings. Those on the inside include chimneys and door and window frames, statues; on the outside there are always cornices under eaves and at floor level made of stucco and brick, balconies, embrasures, statues, balustrades.

Balustrade of the monumental staircase

Fireplace on the piano nobile

Door frames

Frescoes above the monumental staircase - Palazzo Ardinghelli L'Aquila

Fig. 2. Post-earthquake reconstruction 2009 in L'Aquila.

In addition, the quality of the connection of the apparatus to the structure must also be considered in order to define the restoration work:  effective and incorporated into it such as a rose window on a façade, simply connected such as gratings or simply applied to the masonry such as paintings and stuccoes.  ineffectively and of modest strength such as cornices, wooden elements, brick decorations and stuccoes, particularly large ones.  simply leaning without effective structural connections such as leaning altars, chimneys, statues. 3. Analysis of some restoration and seismic improvement of structures and decorative apparatuses In the light of these considerations in this contribution some restoration works with seismic improvement of protected buildings carried out with traditional techniques have been considered, taking into account the historical apparatuses that are most common in professional practice and that are often not taken into account in the calculation codes. 3.1. Vertical Structures As far as vertical load-bearing structures are concerned, a relevant issue concerns the presence of valuable materials on the surfaces (frescoes, plasterwork, ...) and stone elements such as moulded cornices, portals, rosettes, iron gratings. In the case of frescoed surfaces or those covered with valuable plasterwork, consolidation can be carried out with lime injections and/or the use of nanocalcium and, if possible, the insertion of thin stainless steel transverse connections to connect the wall faces. Furthermore, the materials used, needless to say, must be compatible with those in place. The Casino delle Delizie in L'Aquila preserves paintings made with the "buon fresco" technique along the four walls of one room, datable to the late 1500s early 1600s, narrating the "Stories of the Life of Moses" and referable to the school of Raphael, other painted portions are found along the walls where the original staircase leading from the ground floor to the first floor is located. Unfortunately, the seismic event caused severe damage to the entire structure with dramatic consequences on the cycle of frescoes. The consolidation of the masonry, in correspondence of the frescoed walls, was carried out with pre-consolidation injections with nanocalci, natural lime mortar injections and the insertion of stainless steel helical transversal connections arranged and also used for the stitching of the lesions (Fig. 3). The intervention was only carried out on the side where the frescoes were not present.