Caldecott - Basic Structure Completion

The station has achieved completion of the basic structure ahead of schedule with the temporary supports dismantled. Fitting works will begin within the station. Casting of the entrances and ventilation structures are progressing at ground level, with backfilling works at the cripple siding cut and cover tunnel sites nearly completed.

T213 Caldecott Site

Caldecott Cast (VI)

The final concrete pour for the RC roof slab has taken place and the station is on track to achieve structural completion by the beginning of next year. Destrutting of the S1 and removal of king posts are taking place. Backfilling works are in progress at the cut and cover tunnel.

Caldecott Station

Caldecott Cast (V)

Structure of the station is set to be completed by the end of the year as the station's roof slab gets cast concurrent with the strut dismantling works. Works will now focus on the backfilling and superstructure works on the new entrances, together with the A&A works at the Circle Line concourse and subsequent closure and conversion of the existing entrance A into an emergency escape staircase.

Caldecott Station

Caldecott Cast (IV)

The first section of roof slab has been completed at the southern end of the station as structural works take shape.

Caldecott Station

Caldecott Cast (III)

RC works for the station structure is progressing up to the concourse level.

Cross beams cast at Mezzanine 2 level (GL9.5-11.5)

Caldecott Cast (II)

Casting works for the project continues.

Platform, tunnel walls and trackbed completed (September)

Caldecott Cast

Casting works are in progress at the station. Mining of the southbound tunnel at the cripple siding is completed.

Caldecott site illuminated in the west precinct of Toa Payoh

Caldecott Excavation (IV)

Excavation at the Caldecott station is nearly completed, and mining works for the Thomson Cripple Siding have commenced from the south cut and cover tunnel.

Caldecott Excavation (III)

Excavation works are nearly completed at the Caldecott Station. 6 layers of struts have been installed across the span of the station. Similarly on the opposite end of Toa Payoh West, the southern section of the cripple siding tunnel has almost reached the formation level and a gantry crane has been installed to facilitate the remaining muck removal and subsequent mining works.

Caldecott Excavation (II)

Deep excavation works continues at the Thomson Cripple Siding. Installation of struts have almost reached across the entire length of the Caldecott station box.

Rock has been interfaced at this stage of the excavation, and expertise have been called in with the use of special detonators to mitigate the vibration and minimize ground disturbance to the neighbouring skyscrapers, and most importantly the adjacent operational Circle Line.

T213 Caldecott

Caldecott Excavation

Across Toa Payoh West, piling works have completed along the south end of the Thomson Cripple Siding (TCS) and excavation works have commenced. Excavation continues along the north end of the TCS in conjunction with a section of the adjacent station box and entrance which have just commenced excavation in Q2 and is now at S2. Piling works are still on going along Toa Payoh Rise for Entrances C&D.

Shoring works at T213 Caldecott

Telescopic excavation at the north end of TCS

Caldecott Piles & Excavates (II)

Excavation works continue at the Caldecott site. 3 layers of struts have been constructed at its deepest point along the Thomson Cripple Siding. The shoring works at Caldecott are especially unique, where the contractor has bored down tubular concrete piles along the centreline of the earth retaining structure. The bore piles acts as columns supporting the horizontal struttings upon the commencement of excavation. With regards to material and method of construction, this is significantly different from the usual practice of an I-beam (aka king post) driven down to form the vertical component of the shoring structure.

Piling works continue closer to the north.

Caldecott Station, T213

Process of the conventional shoring works elaborated in this animation by Hirose (Singapore)

Caldecott Piles & Excavates

Piling works continue around the station box, including Entrance B across the diverted Toa Payoh Rise. Towards the south, the north section of the Thomson Cripple Siding (TCS)'s ERSS have completed and excavation works commenced with the first layer of struts installed.

Excavation works on the station should commence from the 2nd quarter of this year.

Excavation of north section of TCS - which will link to the south section by mining beneath Toa Payoh West

Piling works commenced on Entrance B across Toa Payoh Rise

Caldecott Piles

Piling works continue at the Caldecott site. The station's ERSS will be constructed using secant bored piles. Multiple cases are currently being driven into the boundaries of the station box and cripple siding tunnel. Toa Payoh Rise has completed its temporary road diversion, for the construction of the two entrances on both sides of the road. The diversion will remain till Q3 2018. Vibration meters have also been installed within the Circle Line station by Ryobi, the monitoring contractor for T212 & T213.

Prior to the commencement of tunnelling from ULS, Samsung would temporary handover site possession (where the original road aligned) to Sato Kogyo to facilitate ground improvement works for TBM docking. This is expected to take place around the middle of 2015 and last a couple of months.

Toa Payoh Rise coming down from Lorong 1

Diverted Toa Payoh Rise

Aerial view of Caldecott

North face

Piling at Caldecott

Caldecott station has seen significant changes to the site since the last review 6 months ago. Numerous crawler cranes and drilling rigs have been positioned around the site following the completion of earthworks and terracing. A road diversion has also taken place along the west bound lane of Toa Payoh Rise.

The 3rd level of the site office at Caldecott houses the project office of LTA's TSL Civil Team 2. This team will be in charge of heading contract T209 to T215 on the client's side.

Update Preview - North facing

Update Preview - South facing

Caldecott - It's Beginning

For our first construction update, we're pleased to say that the line's first site office is already up and operational at Caldecott. Structural works for the site office at Woodlands South have already commenced and should be next in line to be completed. We are anticipating the groundbreaking ceremony to be held here at Caldecott. More information will come in due course.

Some information about T213 
This contract oversees the construction & completion of Caldecott station and the adjacent cripple siding named Thomson Cripple Siding (TCS) to the south. The main span of this 3-trackway cripple siding would be constructed entirely by mining, a first of its kind method ever undertaken here. Two open-cut points will be constructed on either sides of Toa Payoh West, thereby segregating the site area into two. The 134m section between both points will be built with 3 arcs of pipe-roof. The southern point will also facilitate two breakthroughs bored by a single TBM that will launch from Mount Pleasant, under its neighbouring contractor T215.

Works of T213 include the Addition and Alteration (A&A) to the existing Caldecott Circle Line station. Both stations will be linked by a paid subway link. The existing exit A will eventually be downgraded to an emergency exit, while the fare line in the existing station gets reconfigured, including the shifting of faregates, new station control room and removal of existing plant rooms in the CCL station.

TSL Caldecott will have 4 levels (Concourse, Mezzanine 1&2, Platform (TOR 81.60m)) and 2 new entrances constructed on either sides of Toa Payoh Rise.

Aerial Overview of the main site

Caldecott station Pre-Construction

Here are some photos of Caldecott station before it gets torn up again to make way for the Thomson Line construction. Expect more development in this area by the time the Thomson Line is up and running.

01 October 2013