Large culverts made with precast concrete arch-shape elements connected with cast in place concrete.

This paper deals with a new constructive system for large culverts using precast concrete elements. The proposed system includes arch-shaped elements for the main structure and wall elements to retain the earth over this main structure, being all those precast elements connected by cast-in-place concrete. The region of arch crowning receives a layer of cast-in-place concrete to provide transversal distribution of the vehicles concentrated loads and also to increase the cross section height. This paper presents the application of the constructive system for a single span of about 11 meters. It is a crossing over the railway line, with a total length of 25 meters, in the city of Teresina, North-eastern part of Brazil. The thickness of the precast arch is 180mm, reaching 300mm in the region of the arch crowning. The main features and hypotheses used in the structural design are presented. The procedures used for the manufacture of the precast elements and onsite construction are also described.