Seismic risk assessment at local scale. Case-study for a neighbourhood from Ploiesti, Romania

This study presents a seismic risk assessment of the residential building stock located in the Ploiesti-Nord neighbourhood of Ploiesti, Romania, an area significantly impacted by the 1940 and 1977 Vrancea intermediate-depth earthquakes. Site conditions were investigated based on various methods in the literature. The neighbourhood's residential buildings, constructed prior to 1977, primarily consist of five- and ten-story structures built using either masonry or reinforced concrete systems. Unlike previous studies in Bucharest, which evaluated seismic risk at the level of the city's entire building stock, this research focuses on structural typology-specific risk metrics in Ploiesti-Nord, addressing a critical gap in localized seismic risk assessment. The seismic hazard of Ploiesti is exclusively influenced by the Vrancea intermediate-depth source and is comparatively higher than that of Bucharest. Field inspections revealed localized structural interventions still visible on several buildings, though many have undergone thermal rehabilitation. Findings indicate that the highest relative losses and damage levels occur in five-story unreinforced masonry buildings and ten-story reinforced concrete shear wall structures. Conversely, the lowest risk metrics were observed in five-story large panel buildings. Notably, the five-story reinforced or confined masonry buildings, due to their large number of apartments, contribute most significantly to the total seismic losses in the study area. • The seismic risk for a neighbourhood in Ploiesti (Romania) is evaluated. • The buildings in the study area were investigated. • The results show large risk metrics for unreinforced masonry structures. • The lowest seismic risk is observed for large panels structures. • Past seismic damage and interventions are not visible due to rehabilitation.