Design of innovative seismic-resistant steel-concrete hybrid coupled shear walls

An innovative hybrid coupled shear wall (HCSW) system obtained coupling a reinforced concrete wall with two side steel columns connected by means of steel links at each floor is presented. The reinforced concrete wall is designed to undergo limited damages while the steel links connected to the wall are the only dissipative elements and can be easily replaced if damaged after a seismic event. A significant part of the overturning moment is resisted by an axial compression - tension couple developed by the two side steel columns while almost all the horizontal shear and only a fraction of the overturning moment are resisted by the wall. Such hybrid system might represent a cost- and time-effective type of construction since simple beam-to-column connections could be used for the steel frame constituting the gravity-resisting part and traditional and well-known building techniques are required for the reinforced concrete and steel components. The problems encountered in the design of the presented HCSW system are discussed and a specific performance- based design method is presented and applied to the design of a realistic case study. Incremental nonlinear dynamic analyses are performed to assess the behaviour of the proposed innovative structural system in seismic areas and validate the proposed design procedure.