The Hong Kong government has ordered metro operator Mass Transit Railway Corporation (MTRC) to develop “a holistic strategy for assessing the acceptability of the built structures” at Hung Hom Station Extension on the Shatin to Central Link project.
Recent subsidence issues triggered claims over incorrect construction procedures by contractor Leighton Asia during construction in 2015 but the problems only came to light this year.
A commission of inquiry was appointed by the government in July after steel reinforcement in the diaphragm walls was believed to have been cut off too short and was missing coupler to connect with the floor slab. Investigation suggested that there were serious construction flaws and false data had been submitted.
According to the Hong Kong Highways Department, the MTRC could not provide sufficient actual construction records, including the working drawings adopted during the construction period, to verify the condition, works quality and structural safety of the platform and diaphragm wall at Hung Hom.
The government has said that MTRC’s formulation of a holistic strategy is aimed at resolving the issue.
Previous investigations into the construction issues at the site had suggested that the slab and diaphragm walls be broken open to prove the construction. Hong Kong secretary for transport and Housing Frank Chan Fan said cracking open the platform slab is one of the options to consider. He said another choice could be to check the construction documentation and conduct a load test.
In a statement, the government said: “All relevant government departments will conduct a detailed review on the holistic proposal submitted by MTRC and will request MTRC to provide further information if necessary. Upon completion of the review and confirmation of acceptance of the proposal, the government will make the holistic proposal public.”