Out-of-plane buckling instability limit state for boundary regions of special RC structural walls

Abstract

The earthquakes in Chile 2010 and New Zealand 2011 demonstrated the significance of the out-of-plane buckling failure of reinforced concrete structural walls. Past studies have demonstrated that when the out-of-plane deformation is enough to cause instability, loss of vertical load carrying capacity occurs. This paper proposes improvements to an existing wall instability model that estimates the onset of buckling instability. In order to accomplish that objective, a fiber-based computational model is developed to capture the experimental response of twelve reinforced concrete prisms representative of the boundary elements of special planar structural walls with two-layers of reinforcement. The computational model is then employed in a parametric study that aims to improve on an existing out-of-plane buckling instability approach. The computational model is capable of relating the tensile strain developed by in-plane loading to the critical out-of-plane deformation as a function of the prism geometry, the longitudinal and transverse steel contents, and the mechanical properties of materials in the potential buckling region. The proposed approach allows engineers a more accurate means of assessing the parameters that impact the onset of buckling instability.