Rebuilding the Etna Landscape After the 2018 Earthquake: Standards, Geological Surveys, and Retaining Wall Restoration

This study examines the post-earthquake reconstruction framework adopted in the Mt. Etna region, where the ordinances issued by the Extraordinary Commissioner provided the operational structure enabling the integration of technical, geological, and landscape-protection requirements. Geological, geophysical, and geognostic investigations were mandated to characterize local subsurface conditions and ensure that repair or reconstruction works complied with safety standards and regulatory requirements, particularly where retaining walls support buildings, roads, and infrastructure. A distinction was made between traditional dry-stone retaining walls—an essential component of the rural Etnean landscape—and reinforced concrete walls, which are adopted in contexts requiring higher structural performance. Their reconstruction involved differentiated technical approaches aimed at ensuring deformation-compatible behavior and mitigating the effects of permanent ground deformation while preserving the historical and cultural value of dry-stone constructions, recognized as UNESCO intangible heritage. The resulting reconstruction model integrates high-resolution geostructural and geophysical surveys, Active and Capable Fault (ACF) zoning criteria, and performance-based geotechnical design within a unified governance and technical protocol. This approach provides a replicable methodology for the post-seismic reconstruction of retaining walls in areas affected by permanent ground deformation and complex volcano-tectonic settings.