October Tunnel Progress

TEL1/2 Tunnel Chart, October 2015

Contract T206

Excavation of the Changi Bound tunnel by S-893 commenced at the LS2 last month. 15 rings have been erected as of October 12, and 54 rings built as of October 25 (9% completed, ~ 3 rings/day). At the present advance rate, the estimated breakthrough for S-893 is slated around June 2016.

S-894 will commence excavation on the Woodlands Bound tunnel soon.

The T206 project utilizes the steel fibre reinforced concrete (SFRC) segments, a special type of tunnel lining which uses less steel, however is more durable and crack resistant. The segments were previously trialed on the C933 Downtown Line project and the LTA has extended the use of these segments along a 10km stretch of tunnels under the T206 & T207 projects of the Thomson-East Coast Line. The SFRC lining consists of 7+1 segments instead of the usual 5+1. The tunnel lining segments for T206 are currently being supplied by Kimlun in Malaysia.

Progress of S-893 on the Changi Bound tunnel between LS2 to Woodlands (October 24)

Gardens By The Bay D-walls (IV)

Works on the diaphragm wall at the Gardens By The Bay station is nearing completion and excavation works should commence by early next year. A portion of the launch shaft has been partially excavated and shored in preparations for the decking to accommodate the upcoming diversion of Marina Gardens Drive.

The GBME retrieval shaft site across the channel has been hoarded up and a grab is on site to construct the d-wall panels. Ground improvement works continue along the stretch of tunnel route near Entrance C.

Preparations to divert Marina Gardens Drive

Piling at Marina South (II)

Piling works have started at the cut and cover tunnel where the deep soil mixing activities have presumably been completed. Following the realignment of Central Boulevard, the DCM rigs have been re-positioned towards the north over the bored tunnel alignment for the ground improvement works ahead of the TBM drive. Piling and ground improvement works continue at the Marina South station.

Boring Machine Collapse at Bright Hill

One of the boring machines at the T211 Bright Hill site collapsed earlier this afternoon. The collapse pierces through a portion of the gate 6 hoarding and protrudes slightly out onto the pavement. No injuries are reported.

Marina Bay D-walls (IV)

D-walling and ground improvement works continues at the Marina Bay station. The launch shaft seems to have completed excavation works and seems to be in the midst of preparation for the impending handover to T225. A separate shaft to the south is currently being excavated for the future mining of the linkway between TEL and NSL station, beneath the existing NSL and CCL tunnels, which will connect between this shaft and the TBM launch shaft.

Shenton Way D-walls (III)

The diaphragm wall for the Shenton Way station is nearly completed and excavation works are slated to commence by the beginning of next year. Grouting is taking place across the station box. The diversion of the monsoon drain across the central linear park has also been completed.

The tunnel drives for this project have been altered from the initial A/E consultant specifications. Each TBM will now complete the respective upper and lower drives between 2 stations as opposed to completing the tunnels to Maxwell first, before relaunching both machines at Marina Bay.

Marina Bay - Shenton Way Tunnels

Excavation of the launch shaft at Marina Bay is completed and the first STEC EPB TBM is slated to arrive at the site upon handover from Taisei around the first quarter of 2016. Mining of the lower Woodlands bound tunnel should commence by the 2nd quarter thereafter. As of now, ground improvement works continue to take place along the tunnel route beside the Marina One project. Updates on the launch shaft at Marina Bay can be found here.

Shenton Way - Maxwell Tunnels

A section of McCallum St between Boon Tat Link and Robinson Road was closed on September 6 as the project team continues the advanced preparatory works ahead of the TBM launch. An access shaft will be constructed beneath the road to facilitate protection works to the adjacent operational EWL tunnels beneath Robinson Road. The road will reopen by the 4th quarter of 2016 - around the time when the second TBM is expected to launch.

Maxwell D-walls (IV)

Works on the diaphragm wall continues at the Maxwell Station. Preparations for the first diversion of South Bridge Road & Neil Road is underway and should be implemented by month end.

Outram Park Diverts

Several realignments along Eu Tong Sen St and New Bridge Road have been implemented at the Outram Park station site following the relocation of the ERP gantry. The slip road from Outram Road has been diverted beneath the roof of the NEL entrance to allow piling works to take place for the new interchange paid linkways. A realignment along the CTE bound Outram Road is currently being prepared as well.

Pearls Centre have been vacated by the last quarter, and removal of the exterior cladding have commenced under the first phase of the demolishment works. Works on the diaphragm wall continues for the Outram Park station.

Diversion of Eu Tong Sen St & New Bridge Road and upcoming diversion being prepared along Outram Road

Piling at Havelock (IV)

Piling works continues at the Havelock station. The gantry crane has been assembled at the site of the rectangular TBM launch shaft, and on-site casting of the RC ring segments are being carried out. The acoustic screen in front of the Tan Boon Liat building has been completed, and a road realignment to push the carriageways further to the right is being prepared.

Great World D-walls (IV)

Construction of the diaphragm wall at the Great World station has been ongoing for a year now. The completed d-wall of the south launch shaft is visible and excavation should commence soon.

Orchard D-walls (III)

The first traffic diversion for T219 was implemented along Orchard Boulevard last month. The realigned road makes way for the construction of the shaft which will oversee the box jacking construction of the linkways between the existing NSL and the new station.

The 2 international schools have moved out by the start of the 3rd quarter, and preparations for the demolishment works have commenced for the future cut and cover tunnel site. The diaphragm wall of the TBM launch shaft seems to have been completed and excavation works should commence by year end.

T219 Orchard Station

Orchard Boulevard D-walls (III)

Trenching of the Diaphragm Wall & boring works for the bored piles and king posts continue following the diversion of the slip road.