Circle Line Stage 6 added three new stations and 4 kilometers of tunnels to complete Singapore’s 39-kilometer orbital MRT line. We delivered architectural, engineering and sustainability solutions, overcoming complex tunnelling challenges while preserving heritage landmarks and integrating advanced green technologies.
Key Solutions
Delivered architectural, engineering and sustainability designs for safe, efficient and resilient underground transit.
Key highlights
BCA Green Mark Platinum certification
A first for a Land Transport Authority (LTA) MRT project in Singapore
Sky light opening
Allows natural daylight to enter to platform levels, reducing energy use
First centralized cooling system
For three new stations: Keppel, Cantonment, Prince Edward.
The challenge
Delivering new underground stations and tunnels through reclaimed land and a dense urban environment presented complex engineering challenges. The works had to pass beneath the operational Keppel Viaduct and historic Tanjong Pagar Railway Station, while at Keppel an 8-meter-wide outlet drain required temporary diversion and reinstatement above the completed station.
Tunnelling beneath critical infrastructure without disrupting existing operations was one of the biggest challenges.
— Jee Yi Yng (YY), Senior Vice President, Southeast Asia
Our solution
We deployed advanced geotechnical modeling, underpinning works and real-time monitoring to tunnel safely under Keppel Viaduct. Heritage protection at Tanjong Pagar Railway Station included vibration control, canopy dismantling and reinstatement. An innovative stacked tunnel design at Prince Edward Road minimized the footprint and avoided traffic disruption.
Outcome
Circle Line Stage 6 closed missing the link of Singapore’s MRT Circle Line loop, culminating a nearly 30-year journey. The project enhances connectivity between HarbourFront, Marina Bay and the Central Business District, while reducing travel times and easing congestion at major interchanges. It also preserved national heritage and incorporated sustainable technologies.
Key capabilities
We were the overall consultant for the delivery of the project, overseeing and managing the concept, preparing architectural and engineering drawings, calling the tender, providing construction support, as-built documentation, as well as the temporary occupation permit.
Roads, rail and site engineering
Ensuring safe and resilient underground transit works
Architecture
Delivering community-integrated station design
BIM management
Providing lifecycle coordination and digital delivery
Sustainable design
Supporting the achievement of Green Mark Platinum certification
Design management and construction support
Ensuring safe construction and operational continuity
Key technology
Advanced engineering and monitoring technologies ensured safe tunnelling, heritage preservation and sustainable operations.
Finite Element Modeling (FEM)
Simulated ground movement and optimized the tunnel alignment
Real-time Monitoring Systems
Millimetre-precision load transfer and vibration control
Centralized Cooling System
First-of-its-kind for MRT stations, reducing energy use