Structural reliability assessment of a historical reinforced concrete building using numerical analysis and NDT techniques

Abstract This paper presents a case study of a methodology for assessing the structural reliability of an early reinforced concrete structure using a combination of primarily non‐destructive diagnostic and advanced numerical analysis methods. The case study examines the historical Csíky Gergely Theater in Kaposvár, Hungary, built in 1911. At that time, the design methodology and construction process were carried out using a relatively rudimentary standard framework. This study demonstrates that a multi‐phase assessment procedure integrating numerical analysis and primarily non‐destructive testing techniques can significantly reduce structural analysis uncertainty. This approach allows for an optimal selection of the reliability index ( β target ), even when deviating from design standards. Based on this modified reliability index and considering the diagnostic and material test results, the partial factors used for the assessment can be optimally adjusted, and in most cases reduced, compared to those in design codes for new structures. Consequently, the extent of structural interventions needed to increase the load‐bearing capacity can be minimized.