Comparación de voladizos sucesivos "in situ" con voladizos sucesivos prefabricados (Viaducto "d'As Coruxas"; Viaducto del Darro)

Precast cantilever construction method versus in situ cantilever construction method (Viaduct of the Coruxas; viaduc of Darro)

This article compares two bridge construction procedures by cantilever. The construction where segments are concreted on formwork "in situ", versus the construction where segments are precast and erected with a launching girder. As basis of comparison, two similar span bridges constructed simultaneously are used. The Viaduct of Darro in Granada, and the Viaduct of Las Coruxas inm Asturias. A brief description is given of the two construction methods. The differences in Dimensions, Geometric Control, the Schedule and Costs are analyzed. The conclusion is reached that up to a clearance of 125 m, the construction with precast segments takes the half construction time than "in situ" segments. The cost depends on whether the company has skilled workers and equipment for one procedure or another. If the company has both, the cost is about 10 per cent less for precast segments.