Hong Kong rail giant MTR Corporation threatens legal action as probe into shoddy work finds six of 10 steel bars examined in platform were badly installed
- Initial results show first five randomly selected reinforcement bars were not fully screwed into couplers, government confirms
The risks are growing that rail giant the MTR Corporation will have to dismantle at least one platform at Hung Hom station after six of the first 10 reinforcement bars checked in a probe into alleged shoddy construction work were found to be badly installed.
The rail firm, sounding a serious warning for the first time after the first five bars checked were revealed to be substandard, said it was concerned about the work and reserved the right to take legal action against the main contractor, Leighton Contractors (Asia).
“The corporation is concerned that the level of engagement of the five couplers tested so far deviates from the level of workmanship recommended by the [coupler] supplier,” it said in a statement.
Leighton has “the primary responsibility to ensure that all works, including the coupler connections, fully meet the contractual, statutory and workmanship requirements”, it added.
Leighton was not available for comment.
As of Friday evening, six out of 10 rebar samples were found to be below the standard required, the government said. At least 40mm of each bar should be screwed into the coupler, and anything less than 37mm is deemed substandard.
Earlier, the government issued a statement saying initial results from the station showed the first five bars were not fully screwed into couplers near the connection between the east-west platform on the Tai Wai-Hung Hom section of the Sha Tin-Central link, and its supporting diaphragm walls.
The worst case was a steel bar with just 6mm inserted. The other four, as measured by ultrasonic machines, were inserted by 31mm, 29mm, and two at 34mm.
The sixth substandard bar was measured at 36.78mm, while the other four were in the range of 38mm to more than 40mm.
According to the inspection methodology, five substandard bars out of 84 samples for a platform would mean a failure rate of 12.1 per cent.
The investigation is seeking to get to the bottom of allegations of shoddy work on station platforms for the link, Hong Kong’s costliest rail project.
The MTR Corp is in the process of breaking open at least 80 sections of two new platforms at the station for the HK$97.1 billion (US$12.4 billion) link, to see if structural safety has been compromised.
At least 168 coupler connections will be exposed for inspection and a final assessment is expected to be delivered by mid March next year.
Despite its warning, the rail operator insisted it was still too early to draw any conclusions from a small number of samples.
“Different degrees of coupler engagement does not necessarily mean the coupler assembly is ineffective or that there is any safety or structural concern,” it said
Earlier, Secretary for Transport and Housing Frank Chan Fan said the MTR Corp needed to conduct a final analysis of the overall findings before determining the site’s structural safety.
“We are talking about exposing more than 168 steel bars [for inspection]. Only the results of five steel bars have been made public,” he said.
“After digging up the locations and collecting all the relevant findings, the MTR Corp will conduct a final assessment of the structural integrity and conclude whether any remedial works are needed.”
The probe was prompted by a scandal that blew up in May in which the MTR Corp was hit by allegations that steel bars had been cut to imitate proper installation into couplers, and that the structure of supporting diaphragm walls had been changed without authorisation.
The rail operator is now in the early stages of breaking open at least 24 locations along a 400-metre platform for the Tai Wai-Hung Hom section to see if construction details match with amended drawings by Leighton.
Another 56 locations – including 28 on the platform for the Hung Hom-Admiralty section – will also be cracked open to expose at least 168 coupler connections linking to the bars.
Lawmaker Michael Tien Puk-sun described the findings as “strikingly disturbing”, saying it was very likely the whole platform would need to be dismantled for safety’s sake.
“I have consulted three to four experts. Their views are that if the overall failure rate of a platform is higher then 40 per cent, it definitely needs to be torn down and rebuilt. Now it has already reached 12 per cent. I think it’s very likely the platform will need to be demolished,” said Tien, a former chairman of the Kowloon-Canton Railway Corporation, which merged with the MTR Corp.
Veteran structural engineer Ngai Hok-yan called on the government to require the rail operator to unscrew all the problem installations to see if the steel bars were deliberately cut short or if they were caused by poor workmanship.
“Only through this way can we accurately ascertain the structural safety of the platform and identify remedial works,” he said.