Assessment of the Seismic Resistance and Structural Safety of Existing Multistory Residential Buildings

A new methodology for approximate assessment of the seismic resistance or capacity of existing residential buildings incorporating conventional cast in situ reinforced concrete structural systems is presented. It forms a part (Stage 2) of a multistage methodology for seismic assessment and retrofitting of existing buildings, which is being developed by the authors. The methodology is based on concepts of performance-based assessment (PBA) of existing buildings. The expected seismic capacity, as well as the nominal yield and ultimate displacements of the buildings under consideration, are evaluated taking into account the characteristics of the various structural sub-systems (frames, shear walls/shafts) forming together the combined structural system of the buildings under consideration. On the basis of these evaluations, and taking into account the corresponding seismic demand relevant for the buildings under consideration, the expected behavior and structural safety of existing multistory residential buildings in various earthquake scenarios can be assessed. The results of the approximate evaluations compare very well with results of "exact" push-over analyses of the buildings under consideration, performed with the aid of a non-linear computer code.