Required separation distance for reinforced concrete buildings with seismic pounding potential

Abstract

This study aims to investigate the determination of seismic separation distance of adjacent low and mid-rise reinforced concrete (RC) buildings using nonlinear time history analysis. The low and mid-rise RC buildings were reflected using 3, 4, 5, 6, 7, 8, 9 and 10-story buildings designed per 2018 Turkish Building Earthquake Code (TBEC). Beam and column elements are modeled as nonlinear frame elements with lumped plasticity by defining plastic hinges at both ends of beams and columns. The adjacent three-dimensional (3D) building models are connected to each other by linear link elements at the floor levels. 28 different adjacent building models were created by using the RC buildings with different building heights. In order to determine the minimum separation distance between these buildings, an earthquake set compatible with TBEC-2018 was selected. The earthquake set consists of 11 different record pair. Nonlinear time history analyses were carried out for each binary model using 22 acceleration records. The distances necessary to avoid pounding obtained from the result of 616 dynamic analyses were compared with the separation distances defined in the TBEC-2018. As a result of the study, it is seen that the required seismic separation distance per the current code was not enough to prevent pounding. A new simplified equation is proposed based on the period ratios of neighboring buildings for the coefficient (alpha) used in the estimation of gap distances under seismic loads.