Final stretch of the construction site of the T303 Tanjong Rhu & Tunnels

As reminder, the contract for Tanjong Rhu station and tunnels – known as T303 – won by the joint venture Bachy Soletanche Singapore – Wai Fong Construction consists in the delivery of 1km of cut and cover tunnels, a station, and an intake sub-station for the power supply to the tracks.

Work on site started in April 2016. Basic structure completion with the structure completed up to flood protection level is on track.

During this project, the site teams were faced with a number of challenges, especially logistical issues: maintain access to all of the apartment buildings throughout and working in narrow site areas that were restricted by the width of the roads. But also, ground condition, noise… That’s why the site has been split into eight sections to allow the joint venture to plan the work around access for residents and to carry out utility diversion work.

To date, the works carried out are:

• For the station, the diaphragm wall extends to up to 75m depth.
• On the cut and cover tunnel section, a mix of diaphragm wall panels and barrettes, as well as bored piles constructed by our local piling specialist Foundation Alliance.
• The joint venture had to construct a TBM launch shaft for the tunnel drives towards Katong Park station. And soft eyes using glass fibre reinforcement were formed to allow the TBMs completing the tunnels from Gardens by the Bay station to break through into T303 in July.
• Ground improvement work followed the @diaphragm wall construction using a hybrid technique called wet speed mixing which combines jet grouting process with Deep Soil Mixing technique.
• Bulk excavation of the tunnel and station box works have been completed in February.
• Finally, civil engineering works of the station and tunnels, mostly conducted with top-down method, and still on-going to this date.

The next steps are the delivery of the concrete structures, including backfilling to ground level. Structural works are now at their peak, with staggered deliveries of the tunnels, station and entrances in the coming months. These are important deadlines to be met before the project transitions to a reduced team for the remaining two years. Those two years will be devoted to coordinating component suppliers and our own finishing works, at the same time as refurbishment work to roads, stormwater drainage pipes and ground level landscaping.

To know more about the project, read the entire article written by @Claire Smith from Ground Engineering Magazine.