Digital Survey and Structural Investigation on the Triumphal Arch of Caracalla in the Archaeological Site of Volubilis in Morocco: Retracing the Timeline of Collapses Occurred during the 18th Century Earthquake

A low seismic acceleration of just 0.168 g was sufficient to trigger the collapse of the Triumphal Arch of Caracalla in Volubilis during the 1755 Lisbon earthquake, aligning with current Moroccan seismic code estimates for the region. This finding highlights the arch's vulnerability, as its structural capacity matches the expected seismic demand, leaving it at risk from unexpected events. The study combined historical investigations and digital surveys conducted in 2017 with rigorous finite element (FE) modeling—both rigid-block and continuous—to retrace the timeline of collapses caused by subsequent earthquakes. By analyzing these models, researchers determined that the arch's current state reflects a 1930 reconstruction rather than its original condition post-earthquake, underscoring the need for further seismic risk assessment to ensure heritage preservation.

Galassi, S., Bigongiari, M., Tempesta, G., Rovero, L., Fazzi, E., Azil, C., Di Pasquale, L., & Pancani, G. (2024). Digital Survey and Structural Investigation on the Triumphal Arch of Caracalla in the Archaeological Site of Volubilis in Morocco: Retracing the Timeline of Collapses Occurred during the 18th Century Earthquake. Sustainability, Risks and Resilience of Vernacular Heritage, 124–139. https://doi.org/10.4324/9781003475736-8