Assessment of Structural Integrity of Building at 68-74 Thomson Road
Ministry of TransportSpeakers
Summary
This question concerns the demolition of 68-74 Thomson Road for the North-South Corridor (NSC) and potential adjustments to the project's alignment. Ms Poh Li San inquired if earlier structural assessments could have prevented the demolition and if the tunnel route could be shifted away. Minister for Transport Ong Ye Kung explained that while initial tests recommended strengthening, later invasive tests revealed the building’s concrete strength was insufficient. He stated that demolition is necessary for safety and noted that the Building and Construction Authority concurred with this technical assessment. Finally, Minister for Transport Ong Ye Kung clarified that the NSC alignment cannot be adjusted due to dense building constraints and underground MRT tracks.
Transcript
54 Ms Poh Li San asked the Minister for Transport (a) whether a thorough assessment of the structural integrity of the building at 68-74 Thomson Road to withstand the construction of the North South Corridor (NSC) could have been made so that its owners and occupants need not have to move out temporarily and then be told later of the need for demolition; and (b) whether the alignment of the NSC can be adjusted further away to avoid the need to demolish the building.
Mr Ong Ye Kung: A thorough impact assessment study of 68-74 Thomson Road ("the Building") was conducted in early 2020. Inspections and non-invasive tests, in accordance with international practices and guidelines, were conducted. The study found that the Building’s foundation would need to be strengthened to withstand the excavation works for the North-South Corridor (NSC) tunnel and therefore, demolition was not required. To ensure safety during the strengthening works, LTA assisted the occupants to move out of the Building.
However, after the residents had vacated the premises, LTA, as part of its due diligence, conducted further detailed and invasive tests to validate the Building’s concrete strength. It was through these tests that LTA found that the actual concrete strength was lower than required to safely carry out the strengthening works. This test would not have been part of the first test, which was to ascertain if the building foundation requires strengthening in view of the excavation works of the NSC. BCA concurred with the test results and assessment. The Government therefore decided that for safety reasons, the Building has to be demolished before excavation works for the NSC tunnel near the Building can commence.
The NSC alignment was announced in 2011 after an extensive study by agencies and takes into account the fact that the Thomson area is very densely built up with buildings next to the road reserve and underground MRT tracks in the vicinity. Due to site constraints, the two NSC tunnels, one tunnel for each direction of traffic flow, are already designed to be vertically stacked, instead of being built side by side, under the road reserve of Thomson Road. Given these land constraints, it is not possible to adjust the NSC alignment to avoid affecting the Building or other buildings along Thomson Road.