Substandard work on Sha Tin-Central link may have affected a second platform at Hung Hom station, inspection results show
- Highways Department released results for inspections of eight new reinforcement bar samples on Friday
- MTR Corporation is in the process of breaking open at least 80 sections of the two new platforms at the scandal-plagued station
The problems of shoddy work on Hong Kong’s costliest rail project may have affected another platform at the scandal-hit Hung Hom station, investigators have found, sparking calls for more digging.
The discovery came on Friday night as the Highways Department released the inspection results of eight new reinforcement bar samples on two Hung Hom station platforms for the Sha Tin-Central link – five on the north-south platform for the Hung Hom-Admiralty section released for the first time, and three on the east-west platform for the Tai Wai-Hung Hom section.
Among the first five samples for the north-south platform measured by ultrasonic machines, a steel bar was found to be substandard, with only 36.36mm screwed into its coupler without any exposed thread, thus showing signs of being shortened.
According to the supplier, at least 40mm of each bar should be screwed into its coupler, and anything less than 37mm is deemed substandard, taking into account a measurement tolerance of 3mm.
The latest findings brought the total number of faulty bars to 12 of the 39 coupler connections checked, with an overall substandard rate of 31 per cent.
At the east-west platform near the western diaphragm wall, one rebar and a coupler were also found to be unconnected and could not be tested. So far 34 steel bars have been examined at the site, of which 11 were found to be shoddily installed.
The MTR Corporation is in the process of breaking open at least 80 sections of the 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 excavated for inspection and a final assessment is expected to be delivered by mid-March next year.
With more faulty steel bars being unearthed, veteran structural engineer Ngai Hok-yan called on the rail operator to break open more locations for thorough inspection so as to have a good grasp of the safety problems at the station.
He said that so far four substandard bars have been measured without any exposed thread, raising suspicions that they were deliberately cut short.
“With more locations examined, the MTR Corp could make a good analysis of the overall problems and alleviate public concerns over station safety. This will also help the operator to identify effective consolidation or remedial work to fix the deficiencies. The firm could also have more data to make a claim against the main contractor Leighton Contractors (Asia),” he said.
Ngai said the government should also require the MTR Corp to unscrew all the problem installations to have a clear picture of the defective work.
“As the government allows a measurement error of 3mm, it shows that the measurement is not 100 per cent accurate. The best way is to unscrew all problem installations to examine if the faulty steel bars were deliberately cut short or just the results of poor workmanship,” he said.
An MTR spokesman said that during the stage of making a final assessment, the company would consider all options, including extra tests and consolidation works, so as to ensure the station is safe.