Effect of Lateral Torsional Movement of Floors on Pounding Response of Buildings

Abstract

Pounding between adjacent structures is a commonly observed phenomenon during earthquakes, resulting from the out of phase vibration of the structures due to the difference in their dynamic characteristics and mode shapes, while having an inadequate separation distance between them, which can’t accommodate the relative lateral displacement of the buildings, preventing them from vibrating freely and independently of one another which leads to pounding, that can be seen in metropolitan areas, due to the increasing population and the high land values. The study of the pounding phenomena is particularly important as pounding is one of the main reasons that leads to various damages varying from slight architectural damage to severe or even sometimes total structural collapse. Several studies were performed during the last decades on pounding, with the majority simulating the problem in two dimensions (2-D). Although some basic effects of pounding on the dynamic response of buildings can be identified using 2-D simulations, an important factor as in the torsional vibrations and movements of a building (which results from the building’s irregularities or asymmetries in plan) is excluded due to this simplification, and can only be considered while using three-dimensional (3-D) analysis. The main aim of this research is to analyze and study the seismic response due to torsional and lateral pounding between the buildings which are constructed without sufficient seismic gap especially the case of zero gap distance between buildings, due to its wide-spread existence in case of actual buildings built in many cities.