Tuen Mun - Chek Lap Kok Link, Southern Viaducts Section
Ted Lawton | Serdar Dundar
Gammon Construction Limited
Hong Kong, China
PRINCIPAL CONTRACTOR: Gammon Construction Limited
The Tuen Mun – Chek Lap Kok project required the construction of a network of marine viaducts, connecting Hong Kong to mainland China through its new Hong Kong Boundary Crossing Facility (HKBCF). These viaducts are founded on approximately 50 marine pile caps, which normally require large temporary structures such as cofferdams or marine falsework. This structural solution greatly mitigates the shortcomings of these temporary structures by replacing them with pre-cast, pile cap shells, consisting of a base slab and side walls.
The traditional approach to this project would be to construct these pilecaps within large temporary cofferdams, that may have resulted in significant damage to the local marine ecosystem, which includes an endangered species of Chinese white dolphin.
The engineers developed a system for construction of these marine pilecaps, up to 22m x 48m on plan, with precast shell modules that could be simply barged to the piles, joined and stressed together to create a permanent, durable formwork for the pilecap. The modules weight up to 320 tons and can be installed in less than an hour with limited impact on the marine traffic or environment. It is estimated that this construction method, never before used on a project of this scale, saved at least five months of construction time and reduced health and safety risks.