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Thursday, April 11, 2024

J105 - Jurong West & Bahar Junction update Q1 2024

 

18 March 2024 - A view of the progress of work at Jurong West station at end-Q1 2024.

21 March 2024 - Progress of work at Bahar Junction station as of end-Q1 2024.

Work over at contract J105 has seen the roads "dance" as Senior Minister of State for Transport, Amy Khor, described them once during an engagement session for the North-South Expressway. At both station sites, work has seen the diversions of roadways as construction progressed. We'll take a deeper look into the progress made over the first quarter of the year.

JS6 - Jurong West
Jurong West station has seen works progress from the completion of the concourse slab to the beginnings of the platform slab beams that will support the slab over the past quarter. There were also road diversions that saw the road being placed directly underneath the completed concourse slab to free up space at the side table for construction vehicles to be staged for lifting works now that the focus is on the sections above the concourse slab.

10 January 2024 - Work beginning on the concourse level columns in early-Q1.

18 February 2024 - The concourse level columns being prepared for the casting of platform beams
in mid-Q1.

18 March 2024 - Platform slab beams being cast in end-Q1.

Further west, viaduct span construction continues. With a section connected to approximately 4.5 piers now complete, works were focused on stabilising the completed spans and having them bonded together. Over the course of the quarter, work has progressed to include the casting of the portal pier on the side of Jurong West Avenue 2, near the junction just outside the fire station. A second trestle structure was also being assembled ahead of segment launching near the movement expansion joint. Trestles are required to assemble the viaduct spans that are supported by the movement expansion joints as the technique using the hanger beams & lifting frames using a balanced cantilevered method cannot work here.

The movement expansion joint pier crosshead has bearings to allow the viaduct to expand and contract as part of normal movement due to heat. The bearings also allow movement due to trains passing and causing vibration along the viaduct. As a result, the viaduct spans are not fixed into position, unlike a typical pier where the viaduct span is directly bonded to the crosshead. In using the hanger beam & lifting frames, this technique relies on the rigid forces holding the segment in place to support the weight of the beams & frames which is absent when the segments are only supported on the pier by bearings and not bonded to the crosshead.

In view of this, the segments being launched need to be held in position until the span is fully launched and the segments bonded to each other with epoxy. This support comes in the form of the trestle, which supports the bottom of the segments. The trestle can only be dismantled once the entire span is bonded to the neighbouring span on one end and supported by the bearings on the pier crosshead at the other. This process undoubtedly take a longer time than the balanced cantilevered or span by span methods.

10 January 2024 - A view of the completed viaduct spans in early-Q1. Leveling beams are being
used to bond the viaduct sections together.

10 January 2024 - Lifting frames at the first pier west of the station busy constructing the
viaduct spans.

18 February 2024 - A view of the completed viaduct spans in mid-Q1, including the sections
built using the trestle method.

18 February 2024 - The first pier west of the station building with completed spans. The remaining
spans on either side will need to use the trestle method of construction to be completed.

18 March 2024 - A view of the completed section of viaduct spans in end-Q1. Visible in the
distance is a second trestle being installed for viaduct span construction.

18 March 2024 - The first pier west of the station building, not much change as yet.

10 January 2024 - A close up view of the viaduct spans towards the junction of Jurong West
Avenues 2 and 4 with Jalan Bahar & Jalan Boon Lay.

10 January 2024 - A close up view showing the crosshead for the movement expansion joint
already cast but the portal pier beam is still absent.

18 February 2024 - A close up view towards the junction in mid-Q1 shows the installation of
the supporting frames for casting of the portal beam.

18 February 2024 - The supporting frame visible in blue.

18 March 2024 - A close up view shows the second trestle installed for this section of viaduct.

18 March 2024 - A close up view showing the supporting frame for the portal pier beam in place.

JS7 - Bahar Junction
Over at Bahar Junction, the main station building which serves Jurong Pier and Choa Chu Kang-bound trains has completed the concourse slab over the past quarter. With the slab's completion, the westbound carriageway of Jurong West Avenue 4 could be diverted back underneath the completed slab to its original location. This was successfully completed near the end of Q1.

Work on the satellite building of the station which will serve Peng Kang Hill-bound trains is still ongoing with the concourse slab not yet constructed. At this section, the station piers consist of portal piers that will support precast concourse slab spans across the road and junction of Jurong West Avenue 4 with Jurong West Streets 64 & 75. It will be interesting to see the construction of this precast concourse slab by segments being conducted, especially given that the slab will need to support lift and escalator pits as well. If we're not wrong, this will be the first elevated station to use precast segments for the construction of the station slabs.

21 January 2024 - An aerial view of the Bahar Junction station in early-Q1.

18 February 2024 - An aerial view of the Bahar Junction station in mid-Q1. 

18 March 2024 - An aerial view of the Bahar Junction station in end-Q1, with the diverted
westbound carriageway of Jurong West Avenue 4 visible. Also visible is the hanger beam on the
portal beam for the station's satellite building ahead of concourse slab segment launching.

21 January 2024 - A view of the portal pier for the station's satellite building along Jurong West
Street 75 in early-Q1.

18 February 2024  - A view of the portal pier for the station's satellite building along Jurong West
Street 75 in mid-Q1, fully cast.

21 March 2024  - A view of the portal pier for the station's satellite building along Jurong West
Street 75 in end-Q1. Visible are the hanger beams ahead of segment launching for the station's
concourse slab.

21 January 2024 - A view of the station's main building concourse slab in early-Q1.

18 February 2024 - A view of the station's main building concourse slab in mid-Q1.

21 March 2024  - A view of the station's main building concourse slab in end-Q1. Work is in
progress for the concourse level columns that will support the platform slab & trackbeds.

21 January 2024 - A view of the support piers for the station's linkbridge which will connect
the main and satellite station buildings together in early-Q1.

18 February 2024  - A view of the support piers for the station's linkbridge which will connect
the main and satellite station buildings together in mid-Q1.

21 March 2024  - A view of the support piers for the station's linkbridge which will connect
the main and satellite station buildings together in end-Q1.

Viaduct construction has also progressed near the station with several viaduct segments being launched through the first quarter of the year. Work has mostly been concentrated on the north side of the station, along Jurong West Street 75. At the beginning of the quarter, only one pier had segments being launched from it. However, by the end of the quarter, a total of 3 piers had begun such works. In addition, casting was also underway for the pier crossheads for the curve linking the main line with the Choa Chu Kang-bound platform at the station.

21 January 2024 - An aerial view of the pier where the tracks diverge along Jurong West Street 75
in early-Q1. Hanger beams were installed on the crosshead and the first segments were launched.

18 February 2024  - An aerial view of the pier where the tracks diverge along Jurong West Street 75
in mid-Q1. Lifting frames were installed and several segments were launched.

18 March 2024  - An aerial view of the pier where the tracks diverge along Jurong West Street 75
in end-Q1. The lifting frames had been removed and launching of segments was completed.

29 February 2024 - Casting of the crosshead for the section of curved track linking to the station's
main building underway.

18 March 2024 - The completed crosshead for the section of curved track visible as the formwork
is removed.

21 January 2024 - Construction of the pier crossheads was ongoing along Jurong West Street 75.

18 February 2024 - The construction of the crosshead was completed and hanger beams were in
position.

21 March 2024 - Progress of viaduct construction along Jurong West Street 75 as of end-Q1.

At the southern end of the contract, along Jurong West Street 64, work has been concentrated on the portal piers along the roadway. The piers will aid in supporting the tracks converge as they run towards Boon Lay station further south. Neighbouring contract J106 has already completed viaduct span construction on the portal pier that will be handed over to contract J105 to facilitate connection works in time to come.

Meanwhile, work has commenced on installation of the formwork for one of the portal pier beams by the end of the quarter. As the road beneath the pier has been diverted, scaffolding can be used to support the formwork as opposed to steel frames being required, such as is the case for the portal pier near the Jurong West Fire Station.

21 January 2024 - A view of the portal pier along Jurong West Street 64.

21 January 2024 - A view of the portal pier under contract J105 in early-Q1.

21 January 2024 - An aerial view of the 2 portal piers under contract J105 along Jurong West
Street 64. One of the piers' second column is still being cast.

18 February 2024 - An aerial view of the portal piers along Jurong West Street 64 under
construction. The piers in the foreground are for the station while those in the background are
for the viaduct.

21 March 2024 - Scaffolding in place for the construction of the portal pier beam.

21 March 2024 - Another view of the portal pier beam formwork under construction.

Over the quarter, decent progress has been made at the contract's sites. We look forward to the continued progress over Q2 of the year and will be bring you updates in time to come. Do stay tuned!

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