Application of Genetic Algorithm to Optimize Location of BRB for Reinforced Concrete Frame with Curtailed Shear Wall

Abstract

The shear walls are essential seismic elements to increase buildings bearing capacity against earthquakes. In mid- and high-rise buildings, shear walls are subjected to predominant bending deformation under earthquakes, and the responses in upper floors increase. In order to utilize the shear walls appropriately, previous studies proposed to install shear walls until a certain building level, referred to as the curtailed wall. However, the upper frame structure without shear walls suffered significant deformation during earthquakes compared to the lower stories. Therefore, the objective of this study is to present structural configuration for buildings with curtailed shear walls by installing buckling-restrained braces (BRBs) in the upper frame to reduce its deformation under earthquakes. Firstly, the analysis accuracy was verified by simulating the experimental results of four sets of scaled frames with curtailed walls tested on a shaking table. Then, ten- and twenty-story plane frames with the different heights of curtailed walls were created, and their nonlinear responses to earthquake ground motions were evaluated. The genetic algorithm was applied to establish the optimum BRB locations to satisfy the design criteria. It was proved that using BRBs at specific locations in upper frames can significantly improve the seismic response of buildings with curtailed walls.

Optimum buckling-restrained braces application to enhance seismic performance of RC frame with curtailed walls

“…The determination of the concrete and rebar strength and member dimensions refer from the previous study [12], as this study is an extension of previous research. The building has natural period of 0.467 second, and the damping modelled as stiffness proportional damping with coefficient h1 is 0.03 and h2 is 0.02.…”

“…In this study, the strength of BRBs follow Fig. 8 and the adopted parameter component is elaborated in Table 5, which refers to the previous study [12], where the additional maximum shear capacity from BRBs is about 10 percent of the frame shear capacity.…”

“…Table 5. Adopted parameters of BRBs in this study [12]. Step 1: Idealize the location of BRBs using the binary and arrange it as a chromosome, as shown in Fig.…”

“…In this study, the seismic performance of RC frame with curtailed walls, especially at the structure's upper part, is enhanced with additional lateral resisting structures, namely buckling-restrained braces, and popularly known as BRB. This study is extensive research from the previous proposal by the author [12].…”

The Effect of Span-to-Height Aspect Ratio to The Damage Index Ratio of RC Buildings with Vertical Irregularity Setbacks

“…The seismic performance and damage distribution can be used as parameters to determine the effect of the setback existence in buildings. In terms of earthquake loadings, parameter displacement or inter-story drift can be the one representing the seismic performance of building (Maulana, Fonseca & Saito 2022). The damage distribution can also be represented by the story damage index , which can be numerated by using popular damage indices, such as Park-Ang damage index Park, Ang & Wen 1985).…”