The government has accepted a proposal from MTR Corp to conduct a “holistic assessment” of work quality at a Shatin-Central Link (SCL) project site in Hung Hom, a plan that would see the rail operator break open sections of underground platforms for inspections.
At a press conference on Wednesday, officials disclosed that MTR has been given the green light to conduct its planned study that would involve smashing open some concrete slabs for assessing the structural safety of new infrastructure at Hung Hom station.
According to details unveiled at the presser which was attended by officials from MTR and the Highways Department, the whole process is expected to take at least 16 weeks to be completed,
Director of Highways Jimmy Chan Pai-ming told reporters that the proposed holistic assessment strategy was revised from the one that MTR originally submitted on Nov. 23 to the government, after scrutiny by the government and its experts, the Hong Kong Economic Journal reports.
Under the approved revised strategy, MTR will take a three-stage approach for the purpose of verifying the as-constructed condition of the structures, including the platform slabs, at the Hung Hom Station extension that will serve the SCL line.
The first stage includes review of design drawings amended and work records consolidated during construction.
The second stage involves physical investigations, which will see the opening up and inspection of at least 80 locations on the connections between the slabs and the diaphragm walls at the new Hung Hom platforms built for the SCL’s east-west line and north-south line. A larger sampling size may be considered subject to findings of the investigation.
Other irregularities suspected or discovered during the investigation will also be reviewed at the stage.
MTR will then in the third stage consolidate test results and other construction issues found in the first two stages. It will conduct a detailed structural analysis on the Hung Hom Station Extension works to ascertain if the overall condition of the works is acceptable and identify remedial works required if necessary.
Chan said it is a scientific way to use the three-stage approach to identify the problems and the scale of the problems, and the way to resolve the issues found in the Hung Hom Station Extension, which can ensure public safety.
The study will help determine if the structures will meet the required standards.
Providing details for the second stage, Jacob Kam Chak-pui, MTR’s managing director of operations and mainland business, said a spot will be cracked open every seven to eight meters on the east-west line platform and one every 14 meters on the north-south line platform.
As such, the former and the latter will involve 52 and 28 spots, respectively, with at least 168 connections of steel bars to couplers to be exposed in total and examined.
A team from the University of Hong Kong commissioned by the government will be responsible for selecting the spots by random sampling, Kam said, describing the planned method of analysis using random sampling as scientific, rational and objective.
MTR did not elaborate on which party will pay for all the inspections concerned but only said it will hold contractors responsible, based on signed contracts, if any safety issues are found during the inspection process.
As for the concern that the four-month-long investigation may result in delayed opening of the East-West Line, or Tuen Ma Line, which was scheduled to begin service in mid-2019, Kam admitted that MTR is studying, as per the government’s request, the feasibility of launching the line in parts.
But the official added that the goal of opening it all at once from Tuen Mun, the starting point, to Wu kai Sha, the ending point, remains unchanged.
– Contact us at [email protected]