2D vs 3D Models for the Seismic Response Assessment of Reinforced Concrete Framed Structures

Abstract

Earthquakes are serious threat to human lives and infrastructure. The earthquake the struck Albania in November 2019, where 51 people lost their lives and thousands got injured, is a reminder of the tragic impact that the seismic events have on the community. Proper seismic designing of structures on earthquake-prone countries is very important. Engineers aspire new designing methods that shorten the time and reduce the amount of work. In this context, this study was focused on assessing the seismic behavior of three low-to-mid-rise reinforced concrete buildings, ranging from 5 to 12 stories. These structures were represented using three dimensional (3D) frame elements in ETABS. Additionally, two-dimensional (2D) models were generated from the internal frames along two orthogonal directions of the 3D models. Using NONLIN software to perform time history analyses, the study compares the displacement demands obtained by nonlinear time history analyses of both 2D and 3D models to explore the reliability of 2D models in reflecting the behavior of their 3D counterparts. The study considers three types of reinforced concrete buildings, 5, 8 and 12 stories, finding that 2D models effectively approximate 3D model behavior, with average roof drift differences of 0.18% in both directions for 5-storey building, 0.023% and 0185% in x and y directions for 8-storey building and 0.027% and 0.28% in x and y directions for 12-storey building.