Cantilever spar cable-stayed bridge

Cantilever-spar Cable-stayed Bridge
Puente del Alamillo
AncestorCantilever bridge, cable-stayed bridge
RelatedSide-spar cable-stayed bridge
DescendantNone
CarriesPedestrians, Light Rail
Span rangeShort to Medium
MaterialSteel, prestressed concrete
MovableOne example can swing
Design effortHigh
Falsework requiredNo

A cantilever spar cable-stayed bridge is a modern variation of the cable-stayed bridge. This design has been pioneered by the structural engineer Santiago Calatrava in 1992 with the Puente del Alamillo in Seville, Spain. In two of his designs the force distribution does not depend solely upon the cantilever action of the spar (pylon); the angle of the spar away from the bridge and the weight distribution in the spar serve to reduce the overturning forces applied to the footing of the spar. In contrast, in his swinging Puente de la Mujer design (2002), the spar reaches toward the cable supported deck and is counterbalanced by a structural tail. In the Assut de l'Or Bridge (2008), the curved backward pylon is back-stayed to concrete counterweights.