SOUTHEAST ASIA CONSTRUCTION20 Jul 2021
LTA awards contract for Ang Mo Kio station and tunnels under CRL1

Singapore’s Land Transport Authority (LTA) has awarded the civil contract for the design and construction of Ang Mo Kio station and tunnels under the first phase of the Cross Island Line (CRL1) to Gammon Construction and Engineering Pte Ltd - Bachy Soletanche Singapore Pte Ltd Joint Venture.

Totalling S$644 million, the contract will also cover addition and alteration (A&A) works to the existing Ang Mo Kio station along the North-South Line (NSL). When completed, Ang Mo Kio station will be an interchange between CRL and NSL.

Gammon Construction and Engineering has a strong track record of undertaking infrastructure and building projects locally and abroad, said LTA. The company was previously involved in the construction of Chinatown station along Downtown Line and is currently working on the construction of Havelock station and Mayflower station along the Thomson-East Coast Line (TEL).

Bachy Soletanche Singapore, a specialist in geotechnical and civil engineering, is currently involved in the design and construction of the tunnel between Suffolk Walk and Novena Rise for the North-South Corridor. The company is also working on TEL projects such as Tanjong Rhu, Gardens by the Bay and Orchard stations.

Construction works for the CRL1 Ang Mo Kio station are expected to start in the fourth quarter of this year, with passenger service slated for 2030.

‘Challenging ground conditions’

CRL1 Ang Mo Kio station is an underground station located adjacent to the busy junction of Ang Mo Kio Ave 3 and Ang Mo Kio Ave 8. Due to its close proximity to the NSL viaduct and surrounding structures, LTA and the contractor will closely monitor the project’s progress and ensure that all works are executed safely, with minimal impact to existing structures.

“Deep excavation works for CRL1 Ang Mo Kio station will be carried out under challenging ground conditions, as the rock is typically weaker at the transition point between the Old Alluvium (predominantly soil-like material) and Bukit Timah Granite formation,” explained LTA. “This requires the use of specially-designed machinery to carry out the excavation works safely.” 

When completed, the station will have entrances that connect directly to different residential blocks, AMK Hub, Ang Mo Kio Integrated Transport Hub and Ang Mo Kio Town Garden East. Two of the new entrances will be connected to the station via underpasses across Ang Mo Kio Avenues 3 and 8.

To ensure smooth traffic flow on the roads, LTA revealed that these underpasses will be constructed using a ‘pipe-roofing and mining’ method, where a box structure made of pipes will support the ground while mining works are performed beneath the surface of the road. “This method minimises disturbance to the surrounding roads, buildings and underground services, as compared to the more traditional method of open cut excavation from the ground surface.”

LTA added that to facilitate seamless transfer and enhance connectivity for commuters at the station, A&A works will be conducted to retrofit the existing NSL Ang Mo Kio station with additional escalators and reconfiguring of its concourse area. In order to minimise inconvenience to commuters, LTA will plan and coordinate closely with SMRT to carry out majority of the A&A works during non-operating hours.

The CRL is Singapore’s eighth MRT line. It will serve existing and future developments in the eastern, north-eastern and western corridors, linking major hubs such as Jurong Lake District, Punggol Digital District and Changi region. The CRL will have almost half of its stations as interchanges with other rail lines, making it easier and more convenient for commuters to travel across the rail network.

CRL1 is 29 km long and comprises 12 stations from Aviation Park to Bright Hill. This will serve residential and industrial areas in Loyang, Tampines, Pasir Ris, Defu, Hougang, Serangoon North and Ang Mo Kio and benefit more than 100,000 households. With CRL1, common recreational spaces such as Changi Beach Park and Bishan-Ang Mo Kio Park will be more accessible by public transport. Studies on the details of subsequent CRL phases are ongoing.

Images: LTA