Strengthening of Coupled Shear Walls – An overview

Abstract

Coupling beams are considered one of the most important structural elements due to their vital role in resisting lateral loads by improving the overall building stiffness and reducing the impact of the overturning. The resistance of coupled shear walls (CSWs) to earthquakes depends on the coupling beam (CB) for enhancing the ductility of the system and improving the energy absorption capacity. There are two main types of coupling beams; diagonally reinforced coupling beams and conventionally reinforced ones. In the case of diagonal reinforcement, which is being currently recommended by the new design codes, the coupling beams are more efficient in consolidating the walls and providing better performance in resisting earthquakes. On the other hand, the diagonal reinforcing configuration showed some difficulties in terms of construction. There are already existing buildings that have conventionally reinforced coupling beams, which were designed according to the old codes. These coupling beams are in extreme need of strengthening to resist earthquakes. Therefore, some studies have been conducted to find an alternative to the diagonal reinforcing scheme of coupled shear walls. The methods of strengthening differed whether using steel plates or fibre-reinforced polymers sheets. Nowadays Fibre Reinforced Polymers (FRP) are being widely used to strengthen coupling beams and improve the structural behaviour of coupled shear walls. This paper presents a summary of some studies available in the literature concerning the strengthening of the coupling beams and coupled shear walls using FRP. Strengthening method, strengthening configurations, failure modes, and test setups are summarized.