Development of an alternative design for the West Rail viaducts

The Kowloon–Canton Railway Corporation (KCRC) West Rail Phase I project consists of a new 30·5 km long railway in the North West New Territories of Hong Kong. Of the overall route, approximately 13·4 km is elevated on viaduct and station structures. In accordance with the Hong Kong Noise Control Ordinance, the Environmental Protection Department of Hong Kong imposed stringent controls on the noise levels caused by trains running on these viaducts. The conforming design for the viaducts was prepared by KCRC's appointed detailed design consultants. The joint venture contractor, Maeda–Chun Wo Joint Venture, wished to submit a most competitive bid for the viaduct contracts. Robert Benaim and Associates investigated options for an alternative design with the objective of finding a more economic design solution. It would be essential to submit with the tender an authoritative report that analysed the noise and vibration performance of any proposed alternative, and compared this on an equal basis with the performance of the conforming design. The process by which the alternative viaduct design was developed is outlined in this paper.