The MTR Corporation will today begin erecting a wall of steel pilings to protect relics found on the construction site for the future To Kwa Wan station - meaning work on the Sha Tin-Central rail link could resume within weeks.
The decision was made after meetings with the Development Bureau.
Work on the link is already five months behind schedule after the relics, including an ancient well and parts of a building that may date back to the 10th century, were discovered.
However, at a meeting of the Antiquities Advisory Board yesterday, some members voiced concern about the MTR's plans to drive steel piling 12 metres into the ground surrounding the relics.
Dr Philco Wong, MTR's general manager for the project, reassured them technology that cuts out noise and vibrations would be used to protect the relics from damage during the process.
He added that devices to detect vibration and ground settlement would be installed, experienced workers would be deployed to handle the job and there would be full-time supervision of the site. The well would also be filled with sand to prevent distortion and sand bags would be placed on the outside.
The sheet piles would take about two or three weeks to install, he said, and this would then allow the MTR to continue with its tunnel work.
Members were also concerned that the piling would be sunk as close as 1.8 metres to the well. They also asked if the MTR had any contingency plan if abnormal vibration was detected.
Board chairman Andrew Lam Siu-lo responded: "We're not totally without concerns on this option, but we understand it is the best way so far."
Wong said if the vibration level at the site was found to be too high, the MTR would slowly remove the soil surrounding the well before burying the piling. But he added that this method could make the well vulnerable to adverse weather.
He also said that if the relics were to be preserved in situ, the design of the To Kwa Wan station would have to be altered.
At a meeting of the Legislative Council's development panel yesterday, the Development Bureau submitted a document revealing that remains of a water channel system had been found earlier this month near the well.
The system includes a water channel and a tank, and the date and function of it is being studied, it said. Excavation at the area should be completed in autumn, it added.
The document said that the Highways Department and the MTR were studying work adjustment, construction methods and the modification of the station design.
Secretary for Development Paul Chan Mo-po told the meeting that after the excavation, the Antiquities and Monuments Office would study with experts the historic value of the relics. The Antiquity Advisory Board would be consulted before a decision is made on how best to preserve the relics.