Engineering the Tower and Main Span Construction of Stonecutters Bridge

Abstract

Stonecutters Bridge is the second longest cable-stayed bridge in the world and the first major bridge with a twin-box girder superstructure. It has a number of innovative structural features which made the construction of the bridge a significant challenge. This paper describes the fabrication and erection procedures for the bridge towers and the main span superstructure. These were developed in close interaction between the contractor and his construction engineering consultant to ensure a safe and effective construction. A stage-by-stage analysis was set up to model every step of the main span erection. The results were first used in the verification analyses to establish the adequacy of the permanent works throughout construction. In parallel, extensive wind tunnel testing as well as numerical analyses were performed to ascertain the effects of typhoon wind loads on the structure. The structural deformations predicted by the erection analysis were incorporated into a comprehensive geometric control procedure. This paper describes the construction methodolo- gies developed and the related engineering input. It outlines studies undertaken to achieve an effective construction, ensure structural adequacy of all erection stages, ascertain an acceptable aerodynamic performance of the bridge, and exercise full control over the bridge geometry throughout erection.