PSI - Issue 78

Merani Margherita Gabriella Bruna et al. / Procedia Structural Integrity 78 (2026) 785–792

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process of "calibrating" the vulnerability model thus becomes more than just a simple adjustment; it is a fundamental shift toward a more physically grounded assessment. The observed performance of the instrumented building provides the ground truth to validate this T₁ -specific approach. This refined, period-dependent vulnerability model is then used to re-evaluate the damage for all similar, non-instrumented buildings, leading to a more accurate and reliable overall damage scenario. 3. Case study: the Municipality of Sanremo To illustrate the practical benefits and potential of the methodology outlined in Section 2, this section presents a conceptual application to the Municipality of Sanremo. We use the historic 1887 Ligurian Sea earthquake scenario (M w 6.3 and an offshore epicenter with longitude 8.13° E, latitude 43.74° N) as a test case to demonstrate how real time monitoring data could enhance damage assessments. A foundational step for this application has been the establishment of a pilot structural monitoring network. Currently, four buildings, chosen as representatives of the local construction typologies, have been instrumented: Palazzo Bellevue (Sanremo’s town hall), Hotel Alexander, Hotel Marinella, and Hotel Nazionale, as shown in Figure 2. The selection of these buildings was driven by two key criteria: their strategic role in emergency management and their representativeness of the local building stock. Specifically, Palazzo Bellevue is a strategic asset, serving as the city's operational headquarters for emergency coordination, while the hotels are designated to provide shelter for any displaced population (Cattari et al., 2024). Furthermore, they are representative of the area's residential constructions; as can be noted from the diagrams in Figure 2, all four are multi-story structures (exceeding four floors), comprising three masonry buildings and one of reinforced concrete (RC).

Figure 2: A map of Sanremo showing the locations of the four instrumented buildings: Palazzo Bellevue (green box), Hotel Alexander (pink box), Hotel Marinella (yellow box), and Hotel Nazionale (blue box)

Each of these buildings is equipped with a dual-sensor setup: one accelerometer at the base and another at the top. The base sensor is strategically placed to record the seismic input directly at the foundation level. This recording is twofold in its utility: it contributes to the regional seismic network to improve initial estimates of the earthquake's location and magnitude, and it provides a critical "ground-truth" measurement of the actual shaking experienced at the site, which is invaluable for correcting and refining the initial, model-based shakemaps. The sensor at the top of the structure simultaneously records the building’s dynamic response, enabling the identification of its key modal properties, such as natural frequencies and mode shapes. This growing network forms the backbone of our observation-constrained approach, providing the real-world data needed to create "living" damage scenarios. To demonstrate the value of this process, the study was applied to four strategic buildings, which serve as prime candidates for permanent monitoring. For each building, a monitoring system employing high-sensitivity Micro Electro-Mechanical Systems (MEMS) accelerometers was installed. These sensors are specifically chosen for their ability to reliably capture both low-amplitude ambient vibrations for baseline identification and high-amplitude strong motion during an earthquake. The typical installation, shown as an example for Palazzo Bellevue in Figure 3, involves one sensor at the building's base to record ground motion and a second on the top floor to measure the