3rd Croatian Conference on Earthquake Engineering 3CroCEE

The following paper focuses on the conducted performance-based analyses of 8 representative reinforced concrete frame structures. These structures encompass a range of stories, including 2, 3, 5, and 7, and feature varying bay numbers of 3 and 4. The frames are designed to represent the central frame of a reinforced concrete spatial frame structure. The RC frame structures are designed following Eurocode 0 and Eurocode 2 recommendations. The seismic analyses of the RC frame structures are conducted using equivalent lateral force method, in line with Eurocode 8 capacity design recommendations. The analysed frame structures are classified as ductile moment resisting frame structures and it is assumed that they are located in Skopje, N. Macedonia.

Based on the final design of the frame structures, several incremental dynamic analyses on the RC frames have been conducted. The incremental dynamic analyses are performed for four intensity measures: PGA, PGV, the ξ=5% damped spectral acceleration at the respective structure’s fundamental period (Sa(T1, 5%)) and the average spectral acceleration (avg Sa); plotted against the same engineering demand parameter – the maximum peak storey drift of the frame (Ɵmax). The incremental dynamic analyses of the RC frame are performed for 20 ground motion records. The chosen ground motions are obtained from the EU-funded INNOSEIS project. To reduce the computational effort required by the demanding IDAs of multi-degree-of-freedom (MDOF) systems, this paper proposes a simplified and approximate method which is based on the response parameters obtained via a pushover analysis of the respective MDOF system and on the nonlinear dynamic response of the equivalent single-degree-of-freedom (SDOF) system. This paper also presents the obtained IM-based fragility functions of the RC frames, from the performed incremental dynamic analyses on the MDOF systems and on the equivalent SDOF systems. Respective conclusions on the obtained differences of the IM-based fragility functions, have been drawn.