Hong Kong’s embattled rail operator on Thursday dismissed public safety concerns after it emerged that more than 20 areas around its To Kwa Wan station building site had been sinking since construction began six years ago.
MTR Corporation managing director Jacob Kam Chak-pui said the land subsidence related to its scandal-plagued Sha Tin-Central Link, the city’s most expensive rail project, was “a common phenomenon” resulting from piling, excavation and ground water extraction work.
“Things have stabilised, with minor fluctuations in recent periods,” Kam said at a press briefing to announce the firm’s interim results.
He was responding to media reports citing internal MTR documents in 2016 indicating that 23 residential buildings around the station were sinking beyond acceptable limits.
Buildings Department’ guidelines say action must be taken if there is land subsidence of more than 2.5 cm.
According to the reports, BMW House near the new station had sunk by 6.3 cm by 2016.
To Kwa Wan is one of five new stations along the HK$97.1 billion Sha Tin-Central Link, which has been riddled with instances of substandard construction work and unauthorised design changes.
In a late night statement, the MTR Corp said: “According to the records, while the settlement levels of some of the adjacent buildings and underground utilities have reached the set thresholds, the tilting ratios of the buildings have all along met the set requirements, so the works can continue in a safe manner.”
On Tuesday, the government said it had told the rail giant to remove those in charge of the project, while police would investigate “huge discrepancies” and “conflicting reports” in its reports on construction work.
Four senior managers left immediately while the firm’s CEO is due to take early retirement.
Veteran engineer Ngai Hok-yan told the Post that he had seen parts of the internal report from 2016 showing the level of subsidence was above the statutory limit.
He said it was hard to judge from the documents if the structural safety of buildings had been affected, as measurements were taken at only one or two points around each location.
“If the subsidence is even across the whole building, there is no issue,” Ngai said.
However, if different sections of the building were sinking at different levels, this could cause “structural damage” and residents would start seeing cracked walls.
The MTR Corp said it had since received enquiries from some property owners about the impact on their buildings.
“The corporation and the contractor conducted on-site inspections and then referred the cases to an independent loss adjuster for further investigation and follow-up,” the rail operator said. “We have provided relevant data or information to owners of individual residential flats in the past.”
It added that four gas pipes in the area had also been affected by subsidence. While this information was given to Hong Kong and China Gas (Towngas), the city’s dominant gas supplier, with both parties discussing how to take follow-up action, information on another three similar cases was “unfortunately not passed to Towngas”.
However, the locations of the three pipes were in areas that the gas supplier checked daily and its latest data showed settlement had “returned to levels lower than the set thresholds in mid-2017”, the MTR Corp said.
Towngas confirmed it had carried out the necessary repairs and replacements for the four cases of subsidence exceeding statutory limits.
“The situation of gas pipes is stable, the public does not need to worry,” it said on Thursday.
Shell Hong Kong Limited, which operates a gas station at Ma Tau Wai Road next to BMW House, said its premises were not affected.
The HK$4.57 billion contract for the To Kwa Wan and Sung Wong Toi stations was awarded to a joint venture between Hsin Chong Group Holdings and Samsung C&T.
Ngai agreed it was possible the subsidence had stabilised as major construction had been completed.
Pro-establishment lawmaker Michael Tien Puk-sun, chairman of the Legislative Council’s railways panel, said the issue was “ridiculous”.
He suggested the authorities check all stations along the link.
A government spokesman said on Thursday night that the Buildings Department had inspected the 23 buildings named in the documents and found no obvious structural safety problems.