Inspection, structural analysis, and assessment of the existing condition of the tunnel beneath the National Palace of Culture, Sofia, Bulgaria

The current paper considers and summarize the elaborated inspection of the existing condition and operational capacity of the structure of a tunnel beneath the National Palace of Culture and together with the collected data and conclusion concerning the capacity of the top slab of the structure to undertake an additional load from a secondary track from a light rail load. It also includes an assessment concerning the durability of the structure and the compliance with the regulation requirements. The report includes - review and analysis of the available design and other documentation for the site; Surveying and scanning of the main structural elements, incl. localization and registration of visible defects of the structure; performing static and dynamic field testing; structural analysis and calculation of the actual bearing capacity of the reinforced concrete slab of the tunnel according to the regulatory requirements.