Analysis of the Seismic Risk of Low-Code Masonry and Large Panels Structures in Romania

This study focuses on the assessment of the seismic risk of two of the most widely used structural systems in Romania, namely low-rise masonry and large panels structures built before the Vrancea intermediate-depth earthquake of March 1977. Firstly, the seismic capacity is derived based on numerical analyses of several case study structures using dedicated software. Next, the seismic fragility is evaluated using Incremental Dynamic Analysis with a dataset of 45 ground motions recorded during three significant Vrancea intermediate-depth earthquakes. Finally, the seismic risk of the structures is evaluated by convolution between the seismic fragility and site-specific seismic hazard. The results of two damage surveys performed after the March 1977 earthquake in Bucharest and Iasi are used in order to check the impact of this seismic event on the analysed structures. In addition, the impact of the subsequent Vrancea intermediate-depth seismic events of 1986 and 1990 on the analysed case study structures is discussed, as well. The analyses show an increased seismic fragility of the masonry structures as compared to the large panel structure. The results of the seismic risk analyses reveal very large collapse probabilities associated to unreinforced masonry structures from Ploiesti.