Seismic retrofit analysis of concrete coupled shear wall structures with laterally restrained steel plate coupling beams

Abstract

Many existing deep reinforced concrete coupling beams that have low span-to-depth ratios are not desirable for seismic design due to their potential brittle failure with limited ductility and deformability. Previous experimental and numerical studies have demonstrated that the laterally restrained steel plate retrofitting method could effectively enhance the seismic performance of deep coupling beams. This article aims to develop a nonlinear finite element model based on the OpenSees software to accurately predict the behavior of coupled shear walls with or without laterally restrained steel plate coupling beams. The numerical results reveal that the seismic performance of the laterally restrained steel plate retrofitted coupled shear walls can be significantly enhanced. Furthermore, a genetic algorithm is adopted to determine the optimal positions of laterally restrained steel plate coupling beams. It is found that desirable seismic performance can be achieved by retrofitting coupling beams in the middle and higher floors of a building with coupled shear walls. However, only retrofitting coupling beams on the lower floors should be avoided because this could result in the serious degradation of the lateral load-carrying capacity and stiffness of the coupled shear walls.

Externally bonded carbon fiber–reinforced polymer composites for seismic retrofit of reinforced concrete coupling beams designed according to old codes

“…Over the last two decades, several seismic strengthening methods and rehabilitation techniques have been developed to improve the seismic performance of existing CSWs, especially their CBs. The proposed retrofit procedures for CBs include bonding steel plates to one side of the CB (Harries, 1995), upgrading the degree of coupling by adding an optimized number of deep CBs (Chaallal and Nollet, 1997), and bolting steel plates onto the side faces of the CBs with or without adding a buckling restraint device to control plate buckling (Cheng et al, 2018; Su and Cheng, 2011; Su and Zhu, 2005).…”