Marina South - Tunnelling Completes

Tunnelling works for the T227 project have completed, with the breakthrough of the Changi bound tunnel between Marina South and Marina Bay achieved today following the relaunch of the TBM in January. The average advancement rate for the second drive was significantly high at around 7 rings/day.

Breakthrough of CREG TBM at Marina Bay Station on April 14, completing the EPBM's second and final 750m Changi bound tunnel drive between both stations

Marina South Cast (IV)

RC works for the internal structure of the station continues up to the roof slab. The TBM has completed the Woodlands bound drive to Marina Bay and reassembly works for the Changi bound drive have begun with the dismantling of the backup gantries & assembly of the heavy lift crawler crane on site. The relaunch of the TBM is scheduled next quarter - the 2nd last to be facilitated along the TEL1-3.

Marina South station

Marina South Cast (III)

Excavation works for the station zone adjacent to the cut and cover tunnel are progressing down to the formation level. The first completed portion at the center of the station sees the structure cast all the way up to the basement roof slab. Bored tunnelling works on the Woodlands bound drive is on its main drive with a third of the progress completed.

Marina Mall was diverted at the T228 interface at the end of Q3 for the cut and cover tunnel construction adjoining the Gardens By The Bay Station. Backfilling works across the completed portion of the C&C tunnel are underway.

Structure progressing at Marina South

Marina South - TBM Assembly

The 38th and final TBM for the Thomson stretch of the line has finally been lowered and is being assembled at the launch shaft. The CREG EPBM will drive the 750m Woodlands Bound tunnel towards Marina Bay first. Structure of the station continues to be cast, with installation of rebar ongoing at the roof slab level at the highest point. 

Marina Boulevard has been realigned back for shoring and excavation works to proceed for the interconnecting section between the station and cut and cover tunnel. Realignment of Marina Grove is being prepared for similar works to be carried out at the T228 interface.

Marina South Station

Marina South Cast (II)

Casting of the station has reached the concourse level, while portions of the C&C tunnel roof have been completed.

Overview of the T227 open cut excavation site with T228 & T302 in the background

Marina South Cast

Excavation works for the station are nearing completion and falsework is visible at the center zone for the subsequent casting of the concourse level, while rebar installation for the cut and cover tunnel base slab is being done. Launching of the TBM is hindered most likely by the surface ground improvement works, making this the last project to commence any bored tunnel works.

Excavation works at the concourse level at GL10-15

Marina South Excavation (IV)

Excavation works are nearly completed at the S5-S6 layer across the 20m deep station box and cut and cover tunnel.

Excavation works across the Marina South site

Marina South Excavation (III)

Bulk excavation works are underway at the station and cut and cover tunnels. The remaining pipe pile construction is being carried out beneath the former Marina Boulevard.

Excavation works at the cut and cover tunnel

Marina South Excavation (II)

Excavation works commences at the cut and cover tunnel, and continues within the Marina South station box. The formation level at the launch shaft has been reached and casting of the base slab is proceeding. An assembled gantry crane accompanied with the delivered CREG earth pressure balance TBM sits adjacent to the shaft surface. 

Marina Boulevard has been decked and realigned for the remaining pipe pile construction.

Commencement of shoring works for the T227 cut and cover tunnels

Marina South Excavation

Excavation has commenced at the Marina South station and launch shaft, while piling works progress southwards for the cut and cover tunnel. Deep cement mixing activities continue along the tunnel route towards Marina Bay station.

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.

Piling at Marina South

Piling works commenced at Marina South in the 2nd quarter of this year, the last of the 25 contracts to do so. Ground improvement works have commenced along the bored tunnel route to Marina Bay, extending the deep soil mixing activities across the entire 1.5km span of the T227 contract boundary from Marina Bay to Gardens by the Bay.

The team has commenced preparations for the diversion of Central Boulevard at the north end of the station.

T227 Marina South Station

DCM Collapse at Marina South

One of the Deep Soil Mixing rigs collapsed at the Marina South station site earlier this evening. Works at the T227 site have been temporarily halted while the accident investigation is underway. No fatalities have been reported.

Photo Cr: Andy

Photo Cr: Andy

Marina South - Deep Cement Mixing (II)

The cut and cover tunnel to Gardens by the Bay which have been hoarded up, now elongates the worksite boundaries of the T227 project parallel to the Marina Coastal Expressway. Deep Cement Mixing is taking place along the C&C site, in addition to the existing ground improvement works being done at the Marina South Station.

Southern boundary of the C&C tunnel site; Aerial view of the T227 project

Northern boundary of the C&C tunnel site

Marina South - Deep Cement Mixing

The site at Marina South has hyped up in construction activities with the commencement of Deep Cement Mixing and pipe piling works. Above the proposed station box scatters several crawler cranes, pile casings and a drilling rig. Across Central Boulevard, 2 drilling rigs have been positioned on the site of entrance A. The site office for the T227 project is also located here. Across Marina Boulevard, another drilling rig has been positioned at the cut and cover tunnel, near the soon-to-be-demolished MCE project office. 

Yongnam will be involved in the supply and fabrication of steel struts for the shoring works under this project.

T227 Marina South & Cut and Cover tunnel

Marina South Hoards Up

Contract T227 is for the construction of Marina South station, twin bored tunnels north to Marina Bay and a section of cut and cover tunnels from Marina South to Gardens By the Bay. Designed to serve a corner of the future development at Marina South, the station is located at an angle parallel to the MCE under the proposed extension of Marina Mall (road). The design takes into consideration the future Singapore Underground Road System (SURS) which will run beneath Marina Mall such that the concourse & platform level would not be obstructing the future road tunnel.

The station will be 20m deep with 4 basements - UPN linkway (B1), Concourse (B2), Mezzanine (B3) and Platform (B4). Entrances A,B and C will be located along Central Boulevard whilst Entrances D and E will be along Marina Boulevard. 5 vent structures will be built for the station.

Hoardings partially hoarded up around an empty field where the station will be

Bored tunnels
An EPB TBMs will be double driven from a launch shaft at Marina South 850m to Marina Bay. The tunnels will be in a semi-stack configuration when it undercrosses part of a designed pile-free zone of the Common Service Tunnel (CST) Phase 3B that has been specially catered for the tunnels to be bored through. 1 semi-stacked cross passage will be built south of the CST intersection. This is the 48th and final CP to be built within the TSL tunnels.

Cut and Cover tunnels
The tunnels connecting Marina South to Gardens by the Bay (GRB) will be constructed fully by open cut. This is for the construction of a cripple siding and crossover track between both stations. 650m long, the C&C portion is also the 5th and final Temporary Staging Area (TSA) site along the line.

Curvature in the site clearing can be seen for the future Cut and Cover tunnels to GRB

Ccontract boundary between T227 and T228

Update Progress
Being under the last batch of contracts to be awarded, minimal site clearing and hoarding works can only be seen at this point in time. Yongnam had also recently been awarded the subcontract for shoring works under T227.

Final Contract Awards

Today, LTA released the finalized contract awards for the last 3 stations on the Thomson Line. With this, all civil works contracts have been closed and awarded, along with the contract for trackworks, T250.

The contract for T219 which is for the construction of Orchard station and associated tunnels has been awarded to a joint venture between Penta-Ocean Construction and Bachy Solentanche. Both companies have been involved in the construction of Singapore's MRT network. Penta-Ocean is currently working on Bendemeer station along Downtown Line Stage 3 (DTL3) while Bachy Solentanche was involved in the construction of Telok Ayer and Bugis stations on Downtown Line Stage 1 (DTL1). Worth noting is that Penta-Ocean has been the only contractor to bag a contract in each stage of the Thomson Line (TSL).

A view of the exit along Orchard Boulevard

Concourse level view of Orchard interchange station

Entrance along Paterson Road view

Contract T227 is for the construction of Marina South station and associated tunnels. This contract was awarded to a joint venture between Sinohydro Corporation and Sembcorp Design and Construction. As with Napier station, this is Sinohydro's first foray into the Singapore MRT construction market.

Concourse level view of Marina South station

A platform view of Marina South station

Looking down a new road at Entrances A and B

The final contract, T228, is for the construction of Gardens By The Bay station (current terminus of the TSL) and associated tunnels (including tunnels across the Marina Channel, ending in Gardens by the Bay - Bay East). This has been awarded to a joint venture of Nishimatsu Construction and Bachy Solentanche. Nishimatsu Construction is currently involved in the construction of mainline tunnels between Kaki Bukit and Ubi stations on the DTL3 as well as reception tunnels from the Tai Seng Facility Building to Ubi and Bedok North stations.

Concourse level at Entrance C

Entrance C

Contract T250 is for the trackworks along the entire TSL. This has been awarded to CTCI Corporation.

Tunnel Chart for TSL

Here's the tunnel chart organised into two sheets - stage 1 and 2, and stage 3. The exact number for T206 is not known at the moment. A total of 36 TBMs (excluding T206) are set be procured for the entire TSL.

Disclosed Acronyms:

SBAB - Sembawang Airbase

TGR - Tagore

5XO - TS05 Crossover

ULS - Upper Thomson Launch Shaft