Abstract

To facilitate the seismic assessment process of existing, irregular in-plan, reinforced concrete buildings according to Eurocode EN 1998-3, a suitable flowchart is proposed in the current paper. This necessary assessment tool, which is missing from the code, was formulated by examining a set of existing, asymmetric, multi-storey, reinforced concrete buildings, which are seismically assessed according to EN 1998-3 but using a new non-linear static (pushover) analysis procedure suitable for all structural types of asymmetric multi-storey reinforced concrete buildings, torsionally sensitive or not. An intervention strategy to address all the inherent weaknesses of the examined buildings, by adding new structural elements or by strengthening the existing ones with the technique of reinforced-concrete jackets or by combining these methods, was included in the formulation of the flowchart together with all the safety verifications according to EN 1998-3. Finally, a mean elastoplastic-perfect diagram between the effective Peak Ground Acceleration and the average Drift ratio in elevation is presented here, resulted from the capacity curves obtained from the nonlinear static analyses of the “as strengthened” RC buildings. By using this diagram, a preliminary assessment of the quantitative impact of a retrofit study on the seismic capacity of an existing building can be done by performing only linear analyses. This is essential knowledge for the owner of the building, prior to any detailed retrofit design procedure

Keywords:Seismic assessment; Seismic capacity; Pushover analysis; Floor enforced displacements; Capacity curves; Performance levels