Ductility and Overstrength Factor in Seismic Design

This study is conducted to account and evaluate both the overstrength and ductility factors on the dual system reinforced concrete structures with regular and irregular pattern in elevation to show their effect on storey shear as well as storey drift. In this study, three 8-storied frame-wall structures (irregular in elevation) and one 8-storied frame-wall structure (regular in elevation) assumed located in a region of high seismicity all with the plan area of 15 x10 meters are analyzed for their responses to lateral loading by applying biaxial analysis in accordance with the Ethiopian seismic code (ES EN 1998:2015) and Ethiopian code for concrete structures (ES EN 1992:2015). The specified 28 day concrete compressive strength of 30 Mpa and the specified yield stress of the steel 420 Mpa were used. The analysis of structures had been carried out by using finite element soft ware ETABS 2016 Ultimate 16.2.1, which is a structural analysis program for static and dynamic analyses of structures. The weight of the systems had been assumed to consist total dead load, DL plus 20% of live load.