Influence of railings on load carrying capacity of concrete slab bridges

Abstract

This paper presents the results of a parametric study investigating the influence of railings on the load carrying capacity of simply-supported, one-span, multi-lane reinforced concrete slab bridges. A total of 112 bridge cases were modeled using finite element analysis (FEA) subject to AASHTO HS20 truck loadings positioned transversely and longitudinally to produce the maximum bending moments and deflections for cases with and without railings which were compared with AASHTO procedures. Placing two railings on the bridge, AASHTO Standard Specifications procedures overestimated the FEA moments by 100% for one-lane bridges, and by 20% for bridges with two or more lanes. AASHTO LRFD overestimated the FEA moments in all bridge cases by 150% for one-lane, 70% for two-lanes, and a 30% for threeand four-lanes when placing two railings on slab bridges. The results of this study support the AASHTO procedures in designing new concrete slab bridges. However, the paper can also assist engineers in modeling the actual bridge geometry using FEA to account for structural elements such as integral railings in resisting special permit loading on concrete slab bridges. © 2016/2017 - IOS Press and the authors. All rights reserved.