EXPERIMENTAL AND NUMERICAL INVESTIGATION OF AN INNOVATIVE SHEAR WALLS COUPLING FOR ENHANCEMENT OF SEISMIC PERFORMANCE OF RC STRUCTURES

Abstract

In reinforced concrete, buildings there are main structural elements resisting lateral loads such as shear walls and ductile frames. Shear walls are vertical structural members used to resist lateral forces. They resist the lateral loads by a cantilever action. Since the 1970s, tremendous research efforts have been devoted to improve the lateral stiffness of high-rise buildings. These efforts included developing new structural systems making use of the interaction between shear walls and slab-column connection by using a stiff top beam called “Outrigger” extending from the shear wall to the exterior columns placed on each side of the wall and connected rigidly to the wall by the floor slabs or beams. The previously proposed system aimed to make use of the axial forces induced into the exterior columns to carry a portion of the moment generated in the shear walls. One of the main disadvantages of this system is when the connecting floor slabs are not particularly stiff, the effect on exterior columns in lateral load resistance may not be significant. Another disadvantage that the outrigger system have some constraints when we consider the architectural aspects of the building. The space occupied by the concrete beams or steel outriggers trusses places constraints on the use of the floors at which these outrigger are located. Even in mechanical equipment floors, the presence of these outriggers members can be a major problem especially in long spans. Most research efforts focused in their studies on coupled shear walls with stiffening beams. In coupled shear walls architectural requirements lead to repeated openings from floor to floor resulting isolated walls connected by coupling beams. The coupling beams of small span-to-depth ratio enforce the walls to be located in the plan close to each other, which have a bad