Investigation of the effects of short columns on the seismic response of reinforced concrete structures

The formation of the short column phenomenon in reinforced concrete structures has caused design engineers to study the behaviour of such structures. One of the conditions that lead to the formation of a short column is the placement of the structure in a steep position. In this paper, two 8- and 16-story structures were modelled once on a flat surface and again on a sloping site, and their sections were designed using equivalent static analysis. Then, using nonlinear time history analysis, the behaviour of these structures in the plastic region was compared. Structures were modelled in Sap2000v20 software and SeismoSignal.v2018 software was used to scale the accelerometers used in nonlinear time history analysis. Examining the results, it was observed that the formation of short column phenomenon in reinforced concrete structures with special bending frame system has a negative effect on the seismic response of structures; It increases the displacement of the floors, increases the drift of the structure and also creates a mechanism (or the formation of plastic joints). For example, based on the results obtained from 8 and 16 storey structures with and without short columns, it was observed that the average drift of 8 and 16 storey structures with short columns was 19% and 7.1% in the X direction more than the structure, respectively. It has no short columns and also in the Y direction, the average drift of 8 and 16 storey structures with short columns is 7% and 12.8% more than the structure without short columns, respectively.