PSI - Issue 78

Daniele Sivori et al. / Procedia Structural Integrity 78 (2026) 481–488

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1. Introduction This paper illustrates the recent developments of an ongoing five-year project, which represents a collaborative effort involving of the Department of Civil, Chemical and Environmental Engineering (DICCA) and the Department of Architecture (DAD) of the University of Genoa, under the supervision of the Soprintendenza Archeologia Belle Arti e Paesaggio per la città metropolitana di Genova e la provincia di La Spezia (SABAP) to assess the seismic vulnerability and the current structural health condition of one of Genoa’s most important monumental buildings, the Saint Lawrence Cathedral. The project, which began in 2020, involved researchers with heterogeneous backgrounds in studying the various historical phases of construction and restoration that have occurred during the nine centuries of existence of the monument. Several in-situ surveys and experimental tests on the structure, including ambient vibration measurements, have allowed the development of accurate mechanical models of the bell tower to assess the seismic response of this macroelement, considered one of the most vulnerable due to its height, location, and state of degradation (Degli Abbati, Sivori et al. 2024). By encompassing all the elements of the fabbrica as a single, complex system, the project is currently tackling the seismic verification of the entire structure by means of a global finite element model. The great cultural and architectural importance of the monument, coupled with the need to continuously monitor its health condition against factors such as ageing, degradation, changes in environmental conditions, and the effects of natural hazards like earthquakes, has led to the design of a dynamic monitoring system for the whole church, whose installation began in October 2024 and was completed in March 2025. The following Sections discuss the key concepts that guided the design of the monitoring system, emphasizing the technical challenges faced during its implementation and the advantages of employing diverse technological solutions for vibration sensing, focusing on the feasibility of current high-end MEMS accelerometers for the operational monitoring of heritage structures. Vibration data continuously acquired from the system will allow data driven structural health evaluations for the church, enhancing at the same time the reliability of numerical models through vibration-based model updating and structural identification procedures (Cattari et al 2021, Sivori et al. 2024). 2. The Saint Lawrence Cathedral in Genoa, Italy The Saint Lawrence Cathedral (Fig. 1a) is among the oldest monumental structures in Genoa, Liguria Region, Northern Italy, with a deeply layered and complex construction history. Its origins trace back to pre-existing structures from the 6 th century, with the first church mentioned already in 878. The construction of the current Romanesque structure began in the late 11 th century and has undergone continuous transformations, including a major Gothic-style renovation with its iconic black and white bands in the 13th century, Renaissance additions like the dome, and numerous restorations to repair damage from fires, wars and earthquakes — an ongoing process of ageing and renovation that continues to the present day. The cathedral is characterized by a basilical plan with an endonarthex, a transept, and a choir with three apses. The nave is divided into three aisles by two rows of fourteenth-century marble columns, surmounted by false matronea (women's galleries). The lower Gothic part is clearly distinguishable, with its columns and arches featuring black and white stripes, whereas the upper part is composed by a series of superimposed Romanesque round arches in grey stone (11th-12th century). The church plan (Fig. 1b) can be inscribed in a rectangle of 350 roman feet of length and 120 of width, which equals around 78.6 m and 26.95 m respectively. The main nave reaches a height of 27 meters from the pavement, and the main dome rises to over 46 m. The medieval design envisioned two bell towers placed at the opposite ends of the façade, but the left tower was never built. The right one, the bell tower of the church, dates to the beginning of the XIV century and was completed in 1522. The tower has a rectangular plan with approximate dimensions of about 10 m and 12 m for the sides parallel and perpendicular to the façade, respectively. The total height of the tower reaches 63 m above the ground, at the top of the lantern. The structure of the tower is completely embedded in the internal narthex of the church, making the dynamic interaction with the aisles a primary aspect of investigation. Moreover, on the north-east side, the transect is constrained by existing buildings.