Parametric study of position of an outrigger-belt system through pushover analysis

Abstract

This study revolves around the high-rise RCC buildings with lateral force resisting system (LFRS). While constructing a multi-storey building, it is necessary to survey various salient features such as lateral load resistance capacity and lateral stiffness. The LFRS is used to introduce the lateral force resistances in the building and the LFRS used for this study are core and outrigger-belt system. Since the core is applied to the whole building at once, thus application related to it are easier, but when another LFRS (outrigger belt system in this study) which is dedicated to a certain floor, is added in the building, then its position can affect the performance of the building. There has been a lot of theories regarding the optimum positions which show how the position of these storey dependent LFRS can affect the overall performance of the buildings. When a multi-storey building is prone to high intensity earthquake load or heavy wind load, the outrigger-belt and core system would resist the rotation and prevent excessive sway caused by lateral loads. Thus, if proper analysis is performed on the building for optimum position of these systems, then the overall performance can be increased significantly. For this purpose, the buildings of 20-, 25-, and 30-storeys are analysed by Pushover Analysis with two load patterns using Midas GEN. The study is also performed in buildings with different stiffness conditions to understand the overall behaviour of the building for optimum positions. A total of 285 building models are tested using two different load patterns. These buildings differ from each other in terms of position of outrigger, stiffness and number of storeys.