Widening of the Elche de la Sierra Arch Bridge, Spain

Abstract

This article describes the design and construction process for widening a reinforced concrete double-rib arch bridge in Spain. The deck needed widening from 6 metres to 9 metres. The conceptual design involved the construction of a new cast-in-place concrete slab, with the existing deck slab acting as formwork for the central part of the new slab and being incorporated into the structural system of the widened bridge. Structural assessment was conducted to determine whether the bridge in its new construction would be serviceable. This was based on a combined application of deterministic and probabilistic assessment methods, using information from the time of the original construction, a visual inspection and a geotechnical survey. In construction, the existing concrete cover was partially removed to leave strips which assisted in bonding of the new slab. A travelling formwork was used to cast the new deck slab cantilevers. The bridge was load-tested after paving operations were complete.