Design of the new Olifants river arch bridge in the Western Cape province of South Africa

摘要

The existing Olifants river arch bridge, located approximately 300 km North of Cape Town on National Route 7, was constructed in the 1950's and has deteriorated significantly since. Apart from deterioration, the narrow width of the bridge caused a bottleneck due to recent road widenings on the approaches to the bridge. Aurecon was appointed to provide consulting services for the rehabilitation of the existing bridge and for the design of a new arch bridge next to the existing to increase the traffic volume capacity. This paper focuses on the design challenges faced in the design of the new arch bridge. Amongst the challenges were aesthetics, an integral design for minimal maintenance and a long span across the Olifants river. The paper shows how innovative reinforced concrete design can be applied to increase the flexibility of an integral structure of this proportion to reduce the design forces on members and produce a well proportioned and elegant design.