SEISMIC ASSESSMENT AND COST-BENEFIT ANALYSIS OF RETROFITTING MEASURES FOR POST-WAR MULTI-RESIDENTIAL MASONRY BUILDINGS IN LJUBLJANA

This study presents an integrated approach to seismic assessment and retrofitting of multi-residential masonry buildings constructed between 1945 and 1963 in urban centers across former Yugoslavia, focusing on Ljubljana, Slovenia. These buildings, characterized by unreinforced masonry walls and prefabricated floor slabs, represent a significant portion of the urban housing stock and are highly vulnerable to seismic loading. Building on previous research, this paper develops a standardized typology classification and conducts detailed seismic performance assessments using the equivalent frame approach. Four representative building types from Ljubljana are analyzed and modeled using 3Muri software. The effectiveness of various retrofitting strategies, particularly Fibre Reinforced Cementitious Matrix (FRCM) systems, is evaluated for structural improvement and economic feasibility. The study incorporates cost estimations for retrofitting measures based on current market prices, comparing these to potential property value increases and avoided seismic losses. This cost-benefit analysis considers both structural safety and architectural preservation, acknowledging the heritage value of these buildings. Results provide insights for policymakers and stakeholders involved in urban renewal and seismic risk mitigation across former Yugoslavia. The research contributes to developing sustainable strategies for enhancing urban resilience against seismic hazards, balancing safety, economic considerations, and architectural preservation. This approach offers valuable guidance for addressing similar challenges in seismic-prone regions with comparable post-war building stocks.