The man-made island built for the Hong Kong-Zhuhai-Macao Bridge (HZMB) is totally safe and no repairs are needed, Director of Highways Daniel Chung Kum-wah said.
Chung made the remarks on Monday after a visit to the island, which will provide an exit for the undersea tunnel of the bridge.
The official apparently wanted to ease fears among the public that the breakwater may not be strong enough to withstand wave forces, causing the island to be dislocated and posing a threat to those crossing the bridge.
Safety concerns over the mega-bridge, which is expected to open as early as this quarter, have been raised after a photo taken recently by an unmanned aerial vehicle (UAV) and posted on a Facebook page showed some of the concrete slabs that were used to fortify the artificial island had been washed away by sea waves.
The Hong Kong-Zhuhai-Macao Bridge Authority (HKZMBA) explained last week that the slabs were, in fact, placed randomly on purpose as it was the most effective way to weaken the sea waves.
Chung said the placement of slabs follows the original design, which he called “scientific, reasonable and safe”.
He said he was satisfied with the explanations provided by some of the mainland officials at the HKZMBA, Apple Daily reports.
According to the highways chief, there has been no dislocation of the slabs after he and Raymond Kong Tai-wing, chief engineer (major works)of his department, inspected the building plans and photos taken over a period of time.
Kong pointed out that the slabs were stacked for two purposes, absorbing the wave forces and protecting the undersea tunnel.
The design of the slabs enables them to withstand waves that may only be seen “once in 300 years”, Kong added.
Still, some local engineers voiced doubts over the structural soundness of the artificial island.
Civil and structural engineer So Yiu-kwan said he has never heard that wave-weakening slabs can be used to protect the structure of an undersea tunnel, stressing they must be interconnected to be effective, rather than put in a scattered fashion as they are now.
Civil engineer Ngai Hok-yan said each slab weighs five metric tons and can only withstand waves that are four meters’ high at most.
Ngai urged the government to make public underwater photos showing how the slabs are distributed.
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