Multiple plastic hinges concept for seismic demand control in high rise building with irregularities

Abstract

High-Rise buildings with RC-core walls implemented as the lateral load resisting system have been a popular choice of construction in the seismically active areas. Usually, the codes dictate the provision of a single plastic hinge zone at the base of the building to control the seismic demands of these buildings, but multiple research studies have shown that the high-rise buildings are subjected to large seismic forces at points other than the base of the building due to higher modes effects [1], [2]. Due to these higher modes effects, the seismic demands get so high that it can get impractical and uneconomical to design the buildings to resist them. This study aims to implement a method of controlling the unproportionally high seismic demands, named Multiple Plastic Hinges concept, in high rise buildings with irregularities. Locations of these plastic hinges along the height of the building were determined by Response Spectrum Analysis (RSA). A comparison between the single plastic hinge approach and the multiple plastic hinges approach shows that the latter approach results in as much as 24.5% reduction in seismic demands.