Assessment of Shear Wall Quantity in Seismic-Resistant Design of Reinforced Concrete Buildings

It is common to design reinforced concrete buildings with shear walls to resist seismic loads. In the present study, an easy to apply analytical method has been proposed to determine the amount of shear walls necessary to make reinforced concrete buildings seismic-resistant against moderate to severe earthquakes. The method is based on the following design strategy: (1) The total design base shear must be resisted by shear walls; (2) Equal amounts of shear walls must be placed in both orthogonal directions of the structure; and (3) The moment resisting frame elements, which are beams and columns, must independently be able to resist 25 % of the total design base shear. For such a system, the ratio of the total area of shear walls to the area of the floor plan has been obtained by equating the total design base shear to the total shear resistance provided by all shear walls in one direction. Because seismic action may occur in any direction, equal amount of shear walls is recommended to provide in the two orthogonal directions. A procedure is also presented to check the stiffness (or storey drift) requirement for the determined amount of shear walls. The complete analytical procedure was demonstrated by implementing it on a 10 storey 3-D reinforced concrete building.