DEBRIS FLOW BARRIER AT DISCOVERY BAY NORTH DEVELOPMENT: TOWN PLAZA

Discovery Bay is a high-end mixed development situated on Lantau Island, New Territories Region. It is privately developed by Hong Kong Resorts Co. Ltd. (HKR) since 1982. Prior to rapid development at Discovery Bay, the existing terrain is mountainous and there has been incidents of debris flow recorded in the past, near to the development area. To address possible debris flow safety concerns, interception structures on hill slopes shall be provided to capture loose debris, safeguard infrastructure and lives in the event of landslip. HKR has awarded the construction works package for the Discovery Bay North Development to China State Construction Engineering (HK) Ltd (CSCE). For the scope of debris flow barrier design, supply and construct, CSCE engaged G And E Co. Ltd. (G&E) as the specialist contractor to come up with the solution which meets the authorities requirements. Rockfall simulations has been performed and the impact energy identified for open hill slope debris flow is 2,000kJ and channelized debris flow is 5,000kJ. The fence will be located near to the coast, beside Sam Pak Wan Bay, hence needs to be able to withstand salt spray attack.

To meet the project requirements, Maccaferri dynamic barriers has been proposed for the authorities' approval. All major components of the dynamic barriers shall be coated with GALMAC which has proven to provide 3 - 4 times better corrosion resistance than conventional zinc galvanization. After rigorous screening and qualification in terms of product performance and quality compliance, approval was given by Civil Engineering and Development Department (CEDD) Geotechnical Engineering Office (GEO) and Building Department (BD). This has been a landmark project for Maccaferri as Asia's 1st 5,000kJ dynamic barrier to be installed.