Land reclamation the way to go for HKSAR
Advanced tech a boon for massive land reclamation
Hong Kong engineering professionals reckoned that with advanced technologies, the planned “Lantau Tomorrow Vision” reclamation plan could be realized in a safe, eco-friendly and efficient way.
Lawmaker Lo Wai-kwok, who represents the engineering sector, believes the constantly advancing reclamation technologies support the plan’s feasibility, and make Hong Kong more capable of handling challenges in future projects.
“Hong Kong has developed relatively mature skills in artificial island construction. Thus, I believe the island-building plans unveiled by the government will be stable, durable and can withstand extreme weather conditions,” said Lo, former president of the Hong Kong Institution of Engineers.
Geographical and maritime conditions, such as waves and tides, must be taken into account when doing reclamation in Hong Kong, he said. Even under extreme weather conditions, like typhoon or storm surges, many projects could still safeguard people’s safety through precautions like heightening sea walls or placing dolosse (reinforced concrete blocks), he added.
Hong Kong International Airport — a poster child among the city’s reclamation projects — is a good example to the world. The 1,248-hectare airport erected on Chek Lap Kok artificial island is one of the world’s largest and most advanced.
Since it began commercial operations in 1998, the airport has withstood various kinds of adverse weather, including the Super Typhoon Mangkhut, which caused havoc in the city in September last year.
Lo also said he’s confident that new reclamation technologies, which tend to be more eco-friendly, will minimize the environmental impact.
To avoid contamination, the government has adopted the deep cement mixing (DCM) technique, a world-leading non-dredged reclamation method, in the construction of Hong Kong International Airport’s third runway.
This technique injects and mixes cement slurry into unstable soft mud inside the pits on seabed, preventing mud from drifting and contaminating waters, explained Lo.
The cutting-edge skill, which is popular in many developed countries, including the United States, Japan and South Korea, has also been applied in reclamation work to the east of Tung Chung.
Chung Kwok-fai, a renowned structural engineer and vice-president of the Hong Kong Institution of Engineers, told China Daily that the advanced reclamation technologies and upgraded equipment will help slash the time of creating new land.
A long-term land supply option, reclamation often involves decades-long efforts. After preliminary studies, other works in following stages, such as foundation reinforcement, silt filling and infrastructure construction, also could be time-consuming. Among them, waiting for the settlement of landfills alone may take nearly 10 years.
Various new approaches, such as adopting nondredged reclamation methods like DCM, or accelerating the settlement process through a drainage system, or using upgraded dredging vessels with larger capacity, could help shorten the time length for reclamation, Chung reckoned.
He said reclamation projects using DCM could be completed several years earlier than traditional ways, as the technique could enhance the strength and stability of mud in seas, thus saving a considerable time waiting for settlement.