Project: MRT Downtown Line Contract 921 (Singapore)
Ssangyong won the Design & Build contract in 2009, which is a project to support the national infrastructure, estimated to be S$ 803.33 million.
The scope of works also includes the construction of a 130m long section of Future Underground Infrastructure (FUI) above the Rochor Station including new Roadside drain throughout the Contract zone. Deep foundation works for future FUI works are also included at both the LTI and RCR station areas.
Challenges for the Project
Some of the major challenges faced are:
1. Construction of the Little India and Rochor Stations in the heavily built up locality of Serangoon, known to all as Little India, and also a well known tourist attraction.
2. Alteration and Addition (A&A) works to the existing North East Line MRT Station at Little India.
3. Tunneling works under existing live track of North East Line (NEL) Tunnel, 3.5m from crown to NEL tunnel with very strict allowable settlement (11mm for alert level and 15mm for work suspension level).
4. Excavation under existing pedestrian linkway, 5m from the crown with the same criteria for settlement.
5. Encountering boulders during excavation with some boulders more than 3m length. Blasting is not feasible as it will affect the existing NEL station and tunnels.
6. The connecting tunnels between the two stations run along the existing Southbound Carriageways of Bukit Timah Road into Sungei Road. This posed an engineering challenge as the carriageways are the main arterial roads through North-South of Singapore.
7. Being in such close proximity to the arterial roads and the Rochor Canal, there is the constraint of maneuvering heavy machinery safely to ensure that the safety of the public and to minimize disruptions and inconveniences to road users and pedestrians.
8. Managing both noise and vibration generated, due to close proximity to surrounding sensitive structures such as LTA -HSO building, existing NEL
3 MRT Station, HDB flats at Tekka Centre and Rochor Centre, Commercial buildings such as Sim Lim Tower, The Verge and Sim Lim Square and Lasalle College.
9. During excavation, risk of water ingress from the Rochor Canal which is connected directly into the Marina Barrage.
10. Potential ground settlement to the old shop houses around Perak Road areas as these are built on shallow foundations.
11. Obstruction by existing piles foundation of Pedestrian Overhead Bridge at Fu Lu Shou / Rochor Building, as the piles foundation encroaches into the tunnel alignment.
12. Maintaining all 5-lanes carriageway both bounds fully operational at all times.