Inspections at the MTR Hung Hom station expansion showed “deviations” in the steel bars connecting the platform wall to the floor but there was no proof they were cut, Hong Kong’s rail operator said on Monday.
The construction site was part of the HK$97.1 billion Shatin to Central Link, which has been marred by a corner-cutting scandal after a series of reports exposed engineering problems.
The MTR Corporation promised earlier this month to dig up 80 spots in order to check the quality of work, after local media reported that contractors had cut steel bars short instead of correctly screwing them into the couplers connecting the platform wall and the floor.
At least six out of the 10 steel bars selected for random testing had been found substandard. In one case, a steel bar was only screwed into its coupler by six millimetres, falling short of the required standard of 40 millimetres.
On Monday, MTRC Managing Director (Operations and Mainland Business) Jacob Kam expressed disappointment in the project’s main contractor – Leighton Asia – and said it should be held responsible for non-compliance.
“Leighton must take responsibility for overseeing the construction and ensuring its quality. As a large international construction company, Leighton’s performance has been disappointing,” Kam said. “The MTRC reserves the right to take legal action against Leighton in the future.”
Asked whether the platform should be torn down and rebuilt, Kam said that further testing is needed before a holistic analysis could be made.
Lawmaker Tanya Chan had previously floated the possibility that the project might need to be demolished for safety reasons.
Kam claimed that construction quality and structural safety were “two separate concepts.”
“The fact that there are deviations in the construction does not mean the couplers have insufficient load-bearing capability,” he said.
“At this stage, we will consider all options,” Kam added. “For us to jump to any conclusion now will be premature, unscientific and unobjective.”
Yim Kin-ping, an engineering consultant hired by the MTRC, said at the press conference that it was acceptable for the steel bar to only be embedded by 24 millimetres into the coupler.
The Buildings Department had previously said that the steel bars need to be embedded by 40 millimetres.
‘Moving the goalpost’
Lawmaker Michael Tien, who is also a member of the legislature’s railways subcommittee, accused the MTRC of having inconsistent standards.
“They are moving the goalposts again, from 37 millimetres to 24,” Tien said. “But how to change to 24? It’s like a magic trick.”
Tien said the only way to definitively check the condition of the steel bars was to pull them out. The current method of ultrasonic detection could only show the empty space inside a coupler, but there is no telling if the steel bar was cut or just improperly inserted, he said.
Ultrasonic detection also had an error margin of three millimetres, he added.
“They are only talking about the side dish – construction quality,” Tien said, saying that the main question was whether workers had cut steel bars.