SINGAPORE: Construction of the North-South Corridor (NSC) is entering its "most technically demanding" phase, as work progresses amid challenging ground conditions and the unprecedented scale of its viaduct, the Land Transport Authority (LTA) said on Saturday (Sep 12).

At several locations, the corridor has to be built above and below operational MRT tunnels, including those on the North-South and Circle lines. 

Ground conditions have varied considerably along the corridor, with harder rock formations and differing rock profiles complicating foundation, excavation and tunnelling works. This has required additional rock removal, ground stabilisation or changes to construction methods.

Mr Ang Pui Boon, LTA’s second deputy group director for the NSC project, said more challenging ground conditions had been encountered as work progressed.

“We therefore have to make adjustments to our design and construction methods to ensure that the work is carried out safely (without) compromising our surrounding infrastructure.”

CONSTRUCTION ONGOING SINCE 2018

Spanning more than 20km, the corridor is a multi-modal transport link designed to improve connectivity between the northern region and the city, serving towns such as Sembawang, Yishun, Ang Mo Kio, Toa Payoh, Novena and Rochor, while relieving traffic along Singapore’s north-south transport axis.

The project comprises two major structures: an 8.8km elevated viaduct and a 12.3km underground tunnel section. 

Construction has been ongoing since 2018 and will be completed in phases. LTA previously said the viaduct section is expected to open from 2027.

SINGAPORE'S LONGEST VIADUCT

At 8.8km long, about 40m wide and roughly 19m tall – more than six storeys – the NSC viaduct will be Singapore's longest. More than 6,000 precast elements have to be fabricated, transported and installed to form the structure, which LTA said p...