Seismic Capacity Requirements for Low-Rise Reinforced Concrete Buildings Controlled by both Shear and Flexure

Abstract

Lateral-load resisting systems of many low-rise reinforced concrete (RC) buildings are composed of members that may be vulnerable to pre-emptive shear failures, depending on whether their shear strengths are sufficient to develop their flexural strengths (referred to as dual lateral-load resisting system, subsequently); therefore the buildings have a lateral strength associated with the strengths of the components, and the component strengths may be governed by both shear and flexure (the component strengths are referred to as shear and flexural strengths, subsequently). At present there is no effective ways to assess the component strength and ductility of a RC building having a dual lateral-load resisting system. This paper presents a method for determining required shear and flexural strengths associated with structural damage states for various levels of earthquake demand of low-rise RC buildings having a dual lateral-load resisting system. The interaction curves of the required strengths are derived for various ductility ratios based on nonlinear dynamic analyses of the single-degree-of-freedom system. The structural damage states of RC buildings controlled by both shear and flexure are evaluated in terms of the ductility ratio by the procedure outlined by the Japanese Standard. The proposed method predicts reasonably well damage sustained by actual buildings during an earthquake. The proposed method can be used to develop performance-based seismic evaluation and rehabilitation procedures of low-rise RC buildings having a dual lateral-load resisting system.