Piling at Mayflower (II)

Bore piling works continue at the Mayflower site. A second traffic diversion was implemented mid-December at the junction of Street 11, swinging the twin carriageway of Avenue 4 towards the west. The diversion will last for 2-3 months. Instrumentation works have also begun with tiltmeters installed along the columns of the HDB flats surrounding the site.

Penta Ocean from the neighboring contract T211 is also preparing a small site south of Mayflower for preparatory works of the 2 TBMs that will be driven from Bright Hill, both of which will go beneath the foundations of Block 258. More will be shared in the T211 update.

December 24 - Panorama of Mayflower, T210

December 24 - Close up of traffic diversion 1A

Lentor D-walls & Piles

D-walling works at Lentor has commenced this quarter. Close to Yio Chu Kang road, the team is in the midst of constructing the sheet pile for the subway that will link to the station entrance at Calrose. Sheet piles are a favorable method of constructing an ERSS due to the time efficiency in installation and transportation. The interlocking steel segments are also earth tight and water resistant. This method is hence commonly used in shallow linkways and cofferdams.

We expect the completed section of sheet pile to be subsequently decked over by a second and more permanent traffic diversion at the junction of YCK/Ave 4/Lentor Drive next year. This is for the construction of the remaining section of subway beneath the existing diverted road, and subsequently the construction of the entrance at Calrose itself. This diversion would then probably last until the completion of the project.

Sheet piling for the subway leading to the station entrance at Calrose

Panorama of 5XO

At the 5XO site, Avenue 4 was diverted at the end of Q3 and with the site cleared, hoardings are going up along the west side where sheet piling works have commenced. D-walling works should commence from next month as well. To the east, silos and a desander plant have been assembled to support the impending D-wall construction.

Project notice for 5XO (transcript):

- Identified trees along AMK Avenue 4 have been fully removed to facilitate crossover tunnel box construction (5XO)
- Road diversion works at 5XO will be carried out in 2 stages. Traffic Diversion 1 completed on 29 September 2014.
- Traffic diversion 2 at the junction of Avenue 4/5 are planned to commence in early January 2015.
- Tubular pile, steel deck and RC drain has been constructed close to Block 643
- Sheet pile works at Blk 613,614,615 has commenced from mid Dec and will last for a duration of 3 months.
- Installation of monitoring instruments along the ground and buildings
- D-wall works along Blk 613/4/5 planned to commence from end November (delayed)

Tagore Piles & Excavates

Tagore is currently leading in progress due to the large number of equipment brought in by Leighton-John Holland. The ERSS along the south side of the station and launch shaft has completed and excavation works have begun, with the first layer of struts have been installed. Ground treatment works are being done beside the launch shaft as well. Piling works continue at the north side and a desander plant is being constructed next to the Tagore site office.

NFM Technologies has been chosen as the manufacturer to supply 3 Slurry TBMs for T208. Upon completion of the first tunnel towards Lentor, 1 machine will be redriven in the direction of Springleaf. Pigott Shaft Drilling shall supply the slurry treatment plants for the 3 slurry shield machines.

9 piling rigs, 3 crawler cranes and a mobile crane mobilized at the Tagore site

Mock up of 1 one of the 3 NFM Slurry TBMs to be used for T208

Springleaf - Preparations to Divert

At the Springleaf site, construction of the ERSS on the west end of the station has completed. The project team is now preparing to stage a traffic diversion along Upper Thomson Road to construct the remaining portion of the station's retaining wall which lies below the existing road. This impending diversion is expected to be a permanent-temporary one, whereby it will last through most of the duration of the project. The diversion should take place within the next 2 months.

Due to the presence of a launch shaft at the north end that needs to be constructed and handed over to Shimizu of the neighboring contract T207, there is an urgency for the shaft to be done up swiftly. The handover is anticipated to take place around the middle of next year.

D-walling & Piling activities back in October

Preparations to divert Upper Thomson Road (Dec 22)

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

T206 Piles and Excavates

We gear up closer to the commencement of tunnelling works for the Thomson Line in this update. Excavation works for the Launch Shaft 2 (LS2) has just started after 6 months of drilling and piling. STEC has altered the design of the launch shaft from an initial rectangular box proposed by the A/E consultant into a double circular cell - similar to the proposed Dalvey LS at Stevens. The design omits the use of any temporary struts while a permanent concrete beam supports the compression forces of the shaft at its center. This is a significant milestone for the project and we expect excavation works to continue on throughout the next quarter. Works have yet to start on Launch Shaft 1.

T206 Tunnel Chart

Proceeding south, piling works are also in full swing at the Sembawang Airbase (SBAB), escape shaft and Mandai Depot. Kori has been subcontracted by STEC for shoring works under T206. In addition, Kimlun of Malaysia will be supplying the precast tunnel segments for the 10 tunnels within this contract.

Excavation of Launch Shaft 2

Piling works at the Sembawang Airbase C&C site and Avenue 12 Escape Shafts

Piling at Mandai Depot

Woodlands South D-walls

D-walling works for Woodlands South have commenced following the diversion of Avenue 1. 2 hydrofraise machines are currently executing the trenching works. More bentonite silos have arrived on the site and are awaiting to be hoisted up at the junction of Avenue 1/Drive 16.

Aerial view of Woodlands South, T205

3D layout of Woodlands South with respect to the first picture, personally drawn by us using Revit

Additional bentonite silos laying flat on the site 

Piling at Woodlands (II)

Piling works continue on at the Woodlands site with the 6 Bauers. The rigs are now spread out around the station box away from the crossover tunnel during the initial drilling. The site is viewed from a different angle - Causeway Point in this update.

A road notice has been put up informing motorists of the impending traffic diversions at the junction of Avenue 2/5 for the construction of the crossover tunnel, and a completion only in Q4 2017 when the tunnel is expected to have been backfilled. The diversions however have not started.

Woodlands North Terraced

Penta Ocean has almost completed flattening the hill and a little valley has been paved where the rail structure is to be built beneath. The slope along the hills have been terraced into sections with much resemblance to the Caldecott site which shares a similar terrain. Piling works have commenced at the launch shaft by the contractor, while preliminary soil investigation works have begun along the tunnel route from WDN to WDL station.

Kawasaki will be supplying Penta Ocean's Contract T202 with 2 slurry TBMs for the drives from Woodlands North to Woodlands Station, while Pigott Shaft Drilling will supply the slurry treatment plants for the 2 machines.

Woodlands North Site

SI works along the southbound tunnel route, opposite Republic Poly near the launch shaft

POB Progresses @ Napier

Following the successful beam launching works back in October, works to finish up the temporary POB have proceeded on with the completion of the bridge's roof as well as the staircase along the town-bound road. The bus stop at Gleneagles was relocated last month as well. The staircase on the opposite side near the US embassy is still being constructed.

Piling works continues to go on at the launch shaft and exit. 12m high hoardings are also being erected in front of Gleneagles where the former bus bay locates.

Progress of the temporary steel POB

Former bus bay has been demolished at Gleneagles where the 12m high noise barriers are being installed

Piling works continue at the launch shaft