EARTHQUAKE RESISTING POTENTIAL OF INNOVATIVE HYBRID COUPLED SHEAR WALLS WITH LASER-CUT OPEN-TO-CIRCULAR HOLLOW SECTION CONNECTIONS

Abstract

Although conventional reinforced concrete (RC) or hybrid coupled wall (HCW) structures have been used for a number of years as earthquake resistant system in high to moderate seismic areas thanks to their lateral strength, stiffness, and energy dissipation characteristics, some drawbacks such as expensive detailing, costly foundations, large overall weight of the system, difficult restoration works etc. have limited their paramount potential from a structural as well as an economic perspective. In order to minimize these drawbacks and make further advancement, an innovative HCW system is proposed in this thesis consisting of a single RC wall coupled with two steel side circular hollow section (CHS) columns via steel coupling shear critical beams. The RC wall carries almost all the horizontal shear force while the overturning moments are partially resisted by an axial compression-tension couple developed by the two CHS columns rather than by the individual flexural action of the wall alone. The steel coupling beams are bolted to a steel profile either partly embedded in the RC wall or passing through it. Optimized procedures were developed to design both type of connections in an economically efficient manner and also ensuring that the damage always occurs in the steel shear beams (fuses) prior to any damage in the RC wall in general and in the connection zone in particular. Furthermore, this thesis introduces and investigates different types of innovative I-beam-to-CHS-column “passing-through” connections which minimizes the limitations in the existing (or conventional) beam-to-CHS column connections and therefore promote their use in the modern steel industry. Standard design guidelines have thus been developed in accordance with Eurocode provisions for gravitational and earthquake loading scenarios to calculate the ultimate resistances of such joints and are discussed with nonlinear FE simulations verified through experimental results. They are also compared with conventional (direct weld) joints to highlight the newfound advantages.