Design of Approach Slab of Road Bridges

Abstract

This paper deals with the design and assessment of approach slabs of the transition zones of road bridges. The main goal of this article is to evaluate design criteria of this reinforced concrete member with attention to the requirements according to European standards. Up to these days, used procedure for the design of the approach slabs of the bridge construction in Slovakia is based on previous Czechoslovak CSN 73 6244 standard introduced 1981. The reason for using this standard nowadays is mainly because of its simple form as an engineering tool for the design of the geometrical dimension and also the reinforcement of the approach slab. Design procedures used for the analysis are taking into account the simplest and also the most conservative structural schemes, it is the slab with a hinge support in the place of the abutment and the second simple support on the other side substituting the gravel subsoil. This scheme should represent possible consolidation of the embankment under the slab. For more precise description of the behaviour, models with elastic support are used. Using these models, the approach slabs will be analysed for the ultimate limit state. The analysis of the results for various geometrical dimensions could serve as a template for similar design tool, to which bridge designers are used to.