Construction of HK-Zhuhai-Macau Bridge Faces More Challenge, Completion Day: Undetermined

On.cc

3rd November 2015

Construction of HK-Zhuhai-Macau Bridge Faces More Challenge, Completion Day: Undetermined

港珠澳大橋沉管工程難對接 通車無期

Hong Kong-Zhuhai-Macau Bridge (the Bridge) project was scheduled to be completed next year, however given multiple hiccups and challenges, the completion date is yet to be confirmed. Director of Guangdong National Development and Reform Commission (NDRC) Li Chunhong said that due to delays of the immersed tube tunnel (IMT) project. After three months of investigation, the cause of not being able to connect the IMT units is still unsure. Li described that connecting the IMTs is “as difficult as docking and berthing spacecraft”, and whether the Bridge will be in operation next year as scheduled, Li said “difficulty is huge”. When asked if the Bridge will be completed next year, Li said “it is difficult to say”. Legislative Council members expressed their concern, citing that the Bridge’s Hong Kong section has been repeatedly delayed and if the China section is delayed as well, the two sections cannot be connected and causes another budget overrun.

Li Chunhong said in a press conference that the construction of the above sea-level bridge is not an issue, but the challenge is the construction of the underwater tunnel, which needs seabed dredging of 45m to place a total of 33 IMT units amounting to 6.7km long without having any water entering the IMT units. So far, only 14 pieces of IMTs have been connected successfully.

RIGHT: Li Chunhong, Director of Guangdong NDRC

Li also pointed out that tidal movement, current movement, and the number of ships traveling through the site and their speed are all factors that impact the process of seabed dredging. It was scheduled to place the 15th IMT unit last October, but due to the change of sediment accumulation in the seabed trench, despite three months of analysis and investigation, the cause of failing to plan and connect the 15th IMT unit is yet to be determined. “We have used super-computer to simulate all these variables but have yet to find out the cause.”

“Each IMT unit weights 80,000 tones. We need to first complete the seabed dredging, then put the IMT unit in place, and only after that we can connect two IMT units together. The complexity is not far from the docking and berthing between Tiangong and Chang’e,” said Li Chunhong. He also said that they have hired the best consultants, including reclamation and bridge construction experts from the Netherlands, to provide assistance.

Legislative Council member Michael Tien Puk-sun said that even if all the construction works of the Hong Kong section are completed by 2017, the connection problem may still remain unsolved, “if that happens, we can only wait. However, the workers will still need to be paid over the waiting period, the budget overrun will get worse.”

King Wong, Chief Executive & President of Community and Construction Professionals’ Development Centre said that because the main section of the Bridge is located at the major route of the Pearl River Delta, the 6km long underwater tunnel is a must to complete the project. However, the strong current in that area makes construction difficult, plus the constant accumulation of sediment in the seabed trenches, connecting the IMT units is very difficult.

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