Facility Building Fit-Out (II)

Architectural and M&E works continue at the facility building and escape shaft. Trackworks are proceeding towards Springleaf Station from the facility building.

RTS Facility Building

Facility Building Fit-Out

Architectural and M&E works are taking place within the completed structure of the RTS facility building. The completed 2 tunnels from SBAB have been handed over to T250, while FSC works are underway along the 2 tunnels from Springleaf. The launch shaft at Springleaf has also been handed back to T208 for the structural & subsequent backfilling works.

RTS Facility Building

November Tunnel Progress

Bored tunnelling works progresses across the line, with multiple TBM breakthroughs due around the new year of 2018. The Changi bound tunnel was completed at Orchard last month, completing all bored tunnel works under the T219 project - the first project to do so along TEL3.

TBMs with envisaged completion between Dec 2017 and Jan 2018:

T209 TBM 1&2

T212 TBM 1

T215 TBM S-936

T227 TBM 1

T228 TBM 1

TEL1/2 November Tunnel Progress (No change since Sep)

Facility Building Cast (IV)

The T207 project is wrapping up with the completion of bored tunnelling works and the structural completion of the RTS Facility Building. The launch shaft at SBAB has been handed back to T206 following the completed FSC and installation of SWC brackets along the twin tunnels to the Facility Building.

RTS Facility Building

August Tunnel Progress

The 2km long twin tunnels between Springleaf station and the RTS Facility Building have completed under the T207 project. These are the longest single mainline tunnel drives achieved under the MRT construction since the Circle Line 4 project a decade ago. TBM 2 brokethrough the facility building overnight (Jul 31), while TBM 1 completed the Woodlands bound tunnel on July 9.

Together with the completion of TBM C2 at Springleaf under the T208 project, bored tunnelling works are officially completed under the Civil Team 1 projects. With 4 TBM drives completed in July, 6 TBMs remain between 5XO and Caldecott station under Stage 2 of the line.

Envisaged completion for remaining 6 TBMs under TEL2:
T209 TBM 1/2 - Q4 2017
T211 TBM 1 - Sep 2017
T212 TBM 1 - Q4 2017
T212 TBM 2/3 - Q1 2018

TEL1/2 Tunnel Chart, July 2017

T207: TBM 1 breakthrough at Facility Building on July 9 (Photo: Raju)

Facility Building Cast (III)

The full face rock conditions experienced by the final 2 EPBMs from Springleaf have significantly hindered the progress over the last quarter with an average advancement rate of a single ring building per day. TBM 1 is about 30 rings from breakthrough and should complete within a month's time.

Tower crane erected to facilitate the RC works of the facility building superstructure

May Tunnel Progress

Tunnelling works for Stage 1 of the line will be completed by next month with the final 100m long Woodlands bound tunnel being driven between LS2 and Woodlands South station. Concurrently, the twin TBMs from Springleaf will breakthrough at the RTS Facility Building, completing the longest mainline drives (2km) under the TEL project.

TEL 1&2 Tunnel Chart, May 2017

T206: Completed Changi Bound tunnel between LS2 and WDS under the second drive of TBM 4

Facility Building - TBM 3 Breakthroughs

Piling works have recommenced at the facility building site, this time for the superstructural works. TBM 3 has broken through the facility building site from SBAB, while TBM 4 is meters away beneath the Mandai Lake Flyover awaiting settlement remedial actions. TBM 1 and 2 from Springleaf have almost reached the facility building and would complete by the 2nd quarter.

TEL1&2 Tunnel Chart, March 2017

Site filled back for bored pile works for facility building

Facility Building Backfill

Superstructures for the escape shafts are coming up as the TBM main drives are underway. TBM 1 and 2 are now beneath the Seletar Expressway bounded for the RTS Facility Building,  The first breakthrough of TBM 3 and 4 are expected by the next quarter.

Dismantled gantry crane, backfilling and RC works for the facility building

November Tunnel Progress

Tunnelling works for the line have been ongoing for 15 months now. 11 bored tunnels have been completed.

TEL1/2 Tunnel Chart, November 2016

T202 - Breakthrough of TBM 2 at Woodlands Station on October 10. This is the first contract to complete all bored tunnel excavation

Facility Building Cast (II)

The RTS facility building is progressively being constructed upwards. Main drives are underway across all 4 TBMs.

TBM 3 and TBM 4 progress from Sembawang Airbase to RTS Facility Building

TBM 1 and TBM 2 progress from Springleaf Station to RTS Facility Building

RTS Facility Building

July Tunnel Progress

Tunnelling works are underway along all the projects along stages 1 and 2 of the line, with the first slurry TBM for the T211 project launched at Bright Hill this week. 5 bored tunnels have been completed by the first half of the year and a further 5-8 tunnels are envisaged to complete by year end.

TEL1/2 Tunnel Chart, July 2016

T206 - Launch preparations for the second drive of TBM 4 for reception tunnel 1 at Sembawang Airbase C&C (Photo credits: LTA)

Facility Building Cast

Casting of the foundation of the escape shaft at the RTS Facility Building is underway. As of now, the northbound TBM has been launched at Springleaf, and is believed to have similarly launched at the SBAB launch shaft. Ground improvement works are ongoing for the cross passages.

Casting of the lower basement at the RTS facility building site where the 2 northbound TBMs would breakthrough

T207 - TBM Assembly

Both EPB machines at the Springleaf launch shaft have been lowered down. The Woodlands Bound TBM is leading in the assembly works and is expected to launch first by February. 2 gantry cranes have been installed over the launch shaft. Similarly at the SBAB launch shaft, tunnelling works are scheduled to commence soon.

Excavation at the RTS Facility Building is almost completed. Ground improvement works continue at the cross passage locations between the SPL-RTS tunnel route.

Lowering of the bearing of the Changi Bound TBM on Dec 4 (T208 site office)

T207 Excavation

Excavation works commenced at the RTS Facility Building site last month. At the escape shaft site, excavation has reached the formation level and the adit tunnel connecting the ES to the future mainline tunnels are being excavated, way in advance of the tunnel drive.

Ground Improvement Works

Shimizu have commenced ground improvement works above CP5 and CP6 along Mandai Road (near Meng Suan Road) ahead of the commencement of tunnelling between Springleaf and the RTS FB. Ground improvement works by the contractor have also started beside the Springleaf launch shaft.

Excavation at the RTS Facility Building

JTSC TBM - Factory Acceptance

The JTSC TBMs for the T207 project were signed off at the factory acceptance test held north of Suzhou earlier this week. 4 EPB machines were procured by Shimizu for a combined tunnel drive of approximately 6km in length. 2 of these machines will execute the single longest tunnel drive along the Thomson Line between Springleaf Station and the RTS facility building, stretching 2km.

Tunnelling works should commence around the 2nd quarter of 2016.

Scaled model of the T207 JTSC EPBMs

Factory Acceptance Test (Cr: Leong Wei Loon)

Piling at Facility Building (II)

Piling works continue at the RTS Facility Building. A gantry crane has been assembled at the storage site across the road.

Piling at Facility Building

2 piling machines are currently executing bore pile works at the site of the RTS Facility Building. Further north at the escape shaft, the circular earth retaining structure of the shaft seems to have completed and a mini gantry crane has been assembled. Due to the proximity of the escape shaft within the approach of runway 04 at Sembawang Airbase, the shallow gantry crane will facilitate lifting works at the shaft opening in place of a traditional mobile crane.

Shimz's site office for T207 at the north end of the Springleaf site overlooking the future launch shaft that will be handed over to them

Piling at RTS Facility Building

Facility Building Reduces Level

Slope treatment works continue at the RTS Facility Building. The site is currently being excavated to match the reduced level of the Seletar Expressway. Upon completion, piling works will commence on the RTS shaft and subsequently excavation. The site office has also been completed along Upper Thomson Road beside the Springleaf site. The escape shaft site between the RTS and SBAB has been cleared, though no works on the ERSS have commenced. 4 Japanese EPB machines have been said to be procured for this contract, instead of the initial recommendation of slurry TBMs.

Excavation of the RTS Facility Building site

Bentonite Plant

T207 Escape shaft south of SBAB and MDD

Contract T206 & T207

Contract T206

The inaugural tunnel launch for the Thomson Line is expected to be held under this contract at Launch Shaft 2 (LS2), for the launch of 2 TBMs to Woodlands station. Excavation for LS2 is scheduled to begin by the end of the year, and the project team hopes to have the shaft ready to launch the machines in 8-9 months.

T206 Tunnel Chart (Reception tunnels in red)

STEC has recently taken possession of the SBAB site. A crawler crane and 2 piling rigs has been brought in. West of SBAB, the escape shaft at Avenue 12 has also been hoarded up.

Contract T207

At the RTS facility site, a crawler crane has arrived onto the site and piling has begun. Tunnelling will begin slightly later under this contract as both launch shafts is being constructed by the neighbouring contractors requiring a handover process. Site possession under Shimizu is scheduled for end 2015 and early 2016 for the launch shaft at Springleaf and SBAB respectively.

T207 Tunnel Chart

Use of SFRC segments in tunnelling

A new type of tunnel rings have recently been experimented for the first time in Asia under C933 of the Downtown Line. Steel Fiber Reinforced Concrete, or SFRC in short, contains fibrous material and are precast in a (7+1) segment arrangement that distinguishes itself from the conventional RC (5+1) tunnel segments. The fiber reinforcement segment uses less steel, and is much more durable and crack resistant.

Moving forward, LTA continues to expand the use of these rings in the construction of new lines. Contract T206 and T207 were identified contracts to be considered for the usage of the SFRC rings. At the Underground Singapore 2014 conference held last month, the LTA confirmed that 2 TSL contracts will be using the new fibrous segments, doubling the use from 4.7km on the DTL3 to 10km for the new Thomson Line.

RTS Facility Building site alongside the SLE

LS1 and LS2 amidst the diverted Woodlands St 17

Sembawang Airbase & Escape Shaft

Hoarding for Escape Shaft along Avenue 12