Arup was heavily involved in the feasibility study, design and delivery of the Hong Kong Link Road (HKLR), which connects the Main Bridge of the Hong Kong-Zhuhai-Macau Bridge with the Hong Kong Boundary Crossing Facilities (HKBCF) on an artificial island at the north-eastern waters of the Airport Island, opening a direct connection between Hong Kong, Macau and the Western Pearl River Delta Region.
The dual 3-lane expressway comprises a 9.4km viaduct section, a 1km long tunnel as well as a 1.6km long at-grade road section on the reclaimed land.
180m longest bridge span
We proposed a non-dredged construction method for the seawall and reclamation which provides 23ha land area for accommodating the tunnel eastern portal and the at-grade section of the HKLR, associated maintenance facilities and the connection roads between the HKBCF and the Hong Kong International Airport.
Compared with the conventional fully-dredged method, the non-dredged approach minimises sediment dredging and disposal as well as impact on the overall water quality. After looking into various non-dredged methods and their site and environmental constraints, stone column-supported seawall and band drains with surcharge reclamation was finally adopted.
Scenic Hill Tunnel
The HKLR includes a tunnel section which passes through the Scenic Hill, underneath the Airport Road and Airport Express Line (AEL) railway on the Airport Island to minimise environmental and visual impacts to Tung Chung residents. The complex and varied ground properties led to different construction methods for the 1km long tunnel: drill and blast for the Scenic Hill section given the hardness of the rock, mining method for the Airport Road section to maintain the road traffic during tunnelling, whole tunnel box jacking for the AEL section to meet the stringent differential settlement requirements for the railway tracks, and open cut and cover for the new reclamation section with fewer constraints.
The viaduct section features long spans as they cross two navigation channels and the headland between Sha Lo Wan and San Shek Wan – a designated Site of Archaeological Interest – where no bridge pier construction works were proposed to avoid impact. The longest span is up to 180m, setting a new record in Hong Kong for structures of similar types at the time it was erected, and a tailor-made segment lifter was used to install the deck segments for the span above the aforementioned headland.
The span length of typical viaducts has been maximised to 75m long to reduce the number of piers in the western waters for better water quality. Meanwhile, the depth of the viaduct deck remains constant to provide a slim superstructure appearance.
Designed for resilience
The mega structures were built to last 120 years, in accordance with the design standards, capable of withstanding extreme events such as earthquakes and typhoons.