Thompson East Coast Line Contract 309 - Siglap Station - Singapore
Project Detail
Procurement Type: Construct Only
Owner: Land Transport Authority
Construction Cost: SGD 176 Million
NOMA´s client: John Holland - Zhen Hua JV
Design Period: 2016 – Ongoing
Construction Period: 2016 - 2023
Project Phase: Tender and Detailed Design
The Project
The project forms part of the Thomson East Coast Line (TEL), which is a fully underground MRT system. The 43km TEL will add 31 new stations to the existing rail network, with seven interchange stations.
Contract 309 includes the construction of Siglap Station and Entrances, upgrading of an existing canal (Opera Estate Canal), and demolition and reconstruction of access bridges to Victoria School. The project is located mainly along Marine Parade Road with one entrance extending along Siglap Link. The station and entrances are generally constructed following the top-down construction methodology. Diaphragm wall is utilised as the retaining wall during excavation.
At the Western end of the station, Opera Estate Canal upgrading is carried out, which also includes the box culverts under Marine Parade Road. Two access bridges to Victoria School are demolished before commencement of the canal upgrading works. The bridges will be upgraded and reconstructed.
As is typical in Singapore, this project is located in an urban area. The station is to be built underneath a live road and is surrounded by existing residential and public buildings, thus the project requires a thorough traffic and drainage diversion plan and damage assessment. Another challenge in this project is the coordination with the interfacing contracts which include the tunnelling works.
Key Aspects of the Project
- Station and entrances constructed using top-down construction
- Earth retaining system consisting of diaphragm walls with permanent slabs acting as props
- Traffic, drainage and utilities diversion
- Reconstruction of access bridges to Victoria School
- Upgrading of Opera Estate canal and box culverts
- Typical ground condition consists of reclamation fill underlain by old alluvium. Fluvial sand is consistently found between the fill and old alluvium layers. At the Eastern side there are also soft clays (marine clay and fluvial clay) from the Kallang formation.
Scope of Works
NOMA Consulting was engaged by John Holland—Zhen Hua JV to lead the detailed design of the following aspects.
- Design of earth retaining structures to facilitate the diversion works
- Design of earth retaining structures for end parts of Entrances B and C
- Optimization of recharge well design
- Design of soft-eyes with glass fibre reinforced polymer (GFRP) rebar for TBM dockings from the adjacent contracts (C308 and C310)
- Review of geotechnical information and planning of additional site investigation
- Assessment of damage to adjacent structures and services
- Impact assessment of permanent slab opening and design of strengthening to facilitate the top-down construction of the station
- Design of noise barrier
- Design of traffic, drainage and utility diversions
