The Hong Kong government has announced a new mechanism to monitor the sinking – also known as “subsidence” or “settlement” – of MTR railway facilities in light of growing safety concerns.
The policy, announced on Monday, requires coordination between the MTR Corporation, the Electrical and Mechanical Services Department and the Buildings Department. If subsidence beyond acceptable levels is found, an inspection must be conducted within 48 hours and the government must notify the public.
Public and private construction projects located near the MTR’s facilities have been found to cause subsidence at platforms and other structures.
Shortly after the government’s announcement, the MTRC disclosed a list of 64 locations which are being monitored. The MTRC has halted work at three locations after the subsidence had exceeded acceptable levels.
In July, part of the southbound platform at Tai Wai Station sank by 23mm, and the Light Rail Tin Wing stop in Tin Shui Wai sank by 90mm. In June, two bridge columns supporting rail tracks near Yuen Long Station were found to have sunk 20mm over five years.
A government spokesperson said that it was “not rare” for construction work to cause subsidence at nearby structures.
The MTRC released a list of locations on Monday evening that are under “settlement monitoring.” Most issues are along the West Rail Line, which had 15 sites under observation, followed by the East Rail and Ma On Shan lines, with 11.
Other lines affected include the Kwun Tong, Tsuen Wan, Island, South Island, Tseung Kwan O, Light Rail, Tung Chung and Airport Express lines.
The list on Monday revealed no new cases of unacceptable subsidence. However, parts of Kowloon Station are being affected by the nearby M+ museum construction at the West Kowloon Cultural District, and showed subsidence of 17mm. The acceptable limit for subsidence is 20mm.
Less than 10mm subsidence was found in 39 cases, and another five had between 10mm to 17mm.
Pro-democracy lawmaker Roy Kwong, who is also a Yuen Long District Councillor, said on Monday that the MTRC was “moving goalposts” on the acceptable levels of subsidence. He pointed to the case of Tin Wing stop, where the MTRC moved the limit from 20mm to 80mm.
Kwong said he would adopt a wait-and-see attitude towards the monitoring mechanism proposed by the government.