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Category: Rails, Metro and Tunnels

HCMC Metro Line 1: Ba Son Shipyard Station

Posted on by Sir Gwi

HCMC Metro Line 1: Ba Son Shipyard Station

The Ho Chi Minh City Metro is Vietnam’s first rapid transit system, serving the country’s economic and financial capital.

There will be eight lines in the metro system. Lines 1, 2, and 5 are in the implementation stage, while the remaining lines are in the investment planning stage.

Line 1 of the project is 19.7 kilometers long, with a 2.5-kilometer underground segment and a 17.2-kilometer elevated section. Line 1 will run from Ben Thanh Market in the central area to Suoi Tien amusement park in District 9. There are three underground stations within the underground section. Line 1 also crosses the Saigon River.

Line 1 Package 1b comprises the construction of the underground section from Opera House station to Ba Son station, including two underground stations and a 1,315-meter subway tunnel.

The Shimizu-Maeda Joint Operation selected Dextra’s concrete reinforcement solutions to reduce steel congestion in heavily reinforced areas. A total of 230,000 headed bars were delivered and installed for shear link reinforcement.

Río Subterráneo a Lomas Tunnel

Posted on by Sir Gwi

Río Subterráneo a Lomas Tunnel

The Río Subterráneo a Lomas tunnel is a 13.5-kilometer-long tunnel in Buenos Aires, Argentina, which will transport drinking water from the newly expanded General Belgrano Water Treatment Plant in the Quilmes area of Bernal to the city of Lomas de Zamora.

As the main element of the Agua Sur system, a water supply project in Argentina, the tunnel is the country’s largest water infrastructure project in the past 40 years. This new system will provide access to freshwater for 2.5 million inhabitants in the southern region of the Buenos Aires metropolitan area.

For this significant project, Dextra supplied Soft-Eyes reinforced with GFRP (Glass Fiber Reinforced Polymer) bars to facilitate Tunnel Boring Machines (TBMs) breaking through a reinforcement cage.

The project required two Tunnel Boring Machines (TBMs) to be launched and received from shafts. The tunnel was excavated at an average depth of 25 meters, starting with a curve of approximately 400 meters in radius and continuing along a largely straight alignment, with a maximum slope of +/- 2 percent.

The first launch shaft is composed of four circular sectors interconnected at the bottom. The shaft measures approximately 45 meters in length, 12 meters in width, and 25 meters in height.

The entire project is expected to take approximately 10 years to complete.

Dubai Metro

Posted on by Sir Gwi

Dubai Metro

The Dubai Metro is a urban transit rail system operating in Dubai, United Arab Emirates. Two lines are currently operational, the Red Line and Green Line. Additional lines are also planned for coming years.

For the construction of the Red Line, Dextra has been involved between 2005 and 2010 together with the contractors making J T Metro (Obayashi Corporation – Kajima – YapiMerkezi) for the supply of numerous Dextra solutions for various packages and stations.

For the station construction, especially for the foundation works (piles and perimeter d-walls), Dextra supplied its Bartec rebar splicing solutions. Rebar couplers were used for vertical connections in piles D-Walls, columns and piers. Rebar couplers were also used for reconnecting slabs onto the D-Walls. A total of 800,000 Bartec rebar couplers have been supplied for this project, supported by several Bartec equipment sets maintained by local Dextra Aftersales team.

For minor repair applications, RepairGrip couplers were also supplied to splice rebar which had not be prepared with a thread and which had unsufficient produding length to be spliced.

For foundation works as well. Dextra supplied more than 60km of Sonitec sonic tubes, used the CSL integrity testing of piles and walls. Sonitec can be easily assembled at site thanks to their push-fit mouth system, boosting teams productivity and avoiding the tedious task of welding tubes together.

Finally, to accelerate tunneling breakthrough phases and minimize TBMs (tunnel boring machines) time when exiting/entering shafts and stations, Dextra engineered the design of GFRP Soft Eyes and supplied more than 400 km of composite rebar for numerous station packages.

Coimbra B-Portagem Mondego Metro

Posted on by Sir Gwi

Coimbra B-Portagem Mondego Metro

The Coimbra B-Portagem Mondego Metro project is part of the public mass transit system of Coimbra, Portugal. Dextra has played a significant role by providing Sonitec tubes for pile testing.

Dextra supplied Sonitec tubes for testing a total of 67 piles ranging in depth from 12 to 19 meters. The tubes were instrumental in conducting these tests with the Cross-Hole Sonic Logging (CSL) methodology.

The innovative push-fit connection system of Sonitec greatly reduced labor time during installation. Thanks to this user-friendly system, the contractor experienced smoother and more efficient pile testing processes. By eliminating the need for additional labor-intensive procedures, the contractor saved valuable time and resources. It also ensures a secure and reliable connection for pile testing.

London Crossrail

Posted on by Sir Gwi

London Crossrail

London Crossrail (given the name Elizabeth line in 2016) is the largest engineering project in Europe. It is a major part of Transport for London’s investment programme and the largest addition to the transport system in 50 years.

The project consists of a 118-km east-west rail link across Greater London, running from Reading and Heathrow in the west to Shenfield and Abbey Wood in the east.

Since 2009, Dextra has delivered more than 600,000 Griptec connections on more than 20 packages, including stations such as:

  • Liverpool Street,
  • Paddington,
  • Bond Street,
  • Canary Wharf,
  • Royal Oak Portal,
  • Pudding Mill Lane.

Griptec couplers have been used on D-Walls (vertical and horizontal connections), columns, and piles (vertical connections).

Segments of Crossrail were expected to start operating progressively, with full completion scheduled for December 2019.

Panama Metro Linea 1 & Linea 2

Posted on by Sir Gwi

Panama Metro Linea 1 & Linea 2

The Panama Metro is a recently completed urban transportation system in Panama City, the capital of Panama.

Panama Metro Line 1 began construction in 2010 and started operating in 2014. It is 16 km long, with part of the line underground and part elevated.

Following the success of the first line, a second line has now entered the construction phase and was expected to begin operations by the end of 2018.

Pier Columns

For this large construction project, Dextra was involved between 2011 and 2012 (Line 1) and since 2015 (Line 2) for the structural reinforcement of the large pier columns in the elevated sections of the line.

On both lines, the Bartec coupler solution, popular in Panama, was chosen to vertically reconnect the large prefabricated cages made of #11 rebar.

To perform this application, cages are prefabricated on the ground before being split by unscrewing all the couplers on one side.

Once lifted and positioned on top of each other, with the same bars matching those they previously spliced, the cage reconnection can then be made using standard Bartec couplers.

Singapore MRT Downtown Line

Posted on by Sir Gwi

Singapore MRT Downtown Line

MRT Downtown Line is a 44-kilometers fully underground subway line connecting North West and Eastern areas of Singapore main island. With 36 stations, it should ultimately transport more than half a million passengers per day.

The construction of the line has been done by segments. Parts of the line are already operating. Full completion is planned by 2024.

Dextra has been involved since between 2008 and 2011 in the design, engineering and supply of large FRP Soft Eyes for multiple stations packages to the various contractors involved.

A total of 19 Soft-Eyes (2)have been engineered and produced by Dextra for the DTL line. The Soft-Eyes are part of station D-Walls and positioned at station entrance/exit of each station.

A total of 19 Soft-Eyes (2)have been engineered and produced by Dextra for the DTL line. The Soft-Eyes are part of station D-Walls and positioned at station entrance/exit of each station.

Prior to D-Wall construction, Dextra engineers the FRP cage design taking into account size of the TBM, margin for error, soil forces and more design parameters.

Thanks to the properties of FRP material, Tunnel Boring Machines cut through the D-Wall in a minimum time, saving time on schedule and ensuring the perfect condition of the TBM’s head.

In complement of Soft Eyes, Dextra also supplied various subway stations with Bartec rebar couplers.

In D-Walls, rebar coupler (2) are mostly used as a way to perform second stage rebar connection. Once the excavation completed, couplers are used to connect starter bar to the D-Wall in order to build the slabs.

(1)Soft Eye FRP reinforcement in D-Wall before lowering the cage.

(2)Pending rebar couplers for station slab connection.

Chennai Metro

Posted on by Sir Gwi

Chennai Metro

The Chennai Metro is an urban transport system in the city of Chennai, a large and fast-developing city in the south of India. The system comprises four lines, partly underground and partly elevated, and a total of 42 stations. Construction started in 2009, with the first line opening to the public in 2015. The total planned length of the system exceeds 45.1 km.

Underground Stations

For this large construction project, Dextra was involved between 2011 and 2015 in the design, engineering, and supply of 61 FRP Soft Eyes for station entry/exit points as well as TBM insertion/extraction shafts.

Thanks to the properties of FRP material, Tunnel Boring Machines cut through the D-Wall in minimal time, saving time in the schedule and ensuring the perfect condition of the TBM’s head.

Elevated Segments

As a complement to Soft-Eyes for underground parts of the lines, Dextra also supplied Post-Tensioning Bar Systems for permanent applications.

The PT systems connect piles and precast segments of the elevated viaduct (shear key and hold-down applications). Each bar system, composed of high-tensile performance bars, plates, and nuts, is post-tensioned to provide seismic resistance.

For each of the 1,000 sets used on the Chennai Metro, Dextra also supplied the corrosion accessories necessary for this type of permanent application.

D-Walls

Finally, 350,000 Bartec couplers were also used vertically and horizontally in the station D-Walls.

Horizontal connections are performed with couplers left pending. Reconnection is done once the station is excavated, with second-phase rebar being reconnected to start the slabs.

Rio Metro Line 4

Posted on by Sir Gwi

Rio Metro Line 4

Rio de Janeiro Line 4 is a subway line that is partly elevated and partly underground, with two segments. The line was planned to open for the 2016 Rio de Janeiro Summer Olympics.

Dextra was involved between 2013 and 2015 in the design, engineering, and supply of four large FRP Soft-Eyes for station entry/exit points. These Soft-Eyes were the first ever delivered on the South American continent.

Prior to D-Wall construction, Dextra engineered the FRP cage design, taking into account the size of the TBM, margin for error, soil forces, and other design parameters.

Thanks to the properties of FRP material, Tunnel Boring Machines cut through the D-Wall in minimal time, saving time in the schedule and ensuring the perfect condition of the TBM’s head. The time factor is especially important in humid environments such as Rio to limit water entry into the station excavations.

On this project, Dextra also supplied Rolltec Rebar Couplers, used as vertical connectors in the station diaphragm walls to reconnect cages.

Couplers were also used horizontally to reconnect slabs at station level and at the surface in the D-Walls.

Nagpur Metro, Reach-1 (Line 1)

Posted on by Sir Gwi

Nagpur Metro, Reach-1 (Line 1)

Nagpur, the second capital of Maharashtra and one of the fastest developing cities in India, is witnessing major growth in terms of infrastructure. The development primarily focuses on connectivity, with the Metro rail playing a major role.

Launched in 2016, the metro project has been widely praised for its speed of execution and the quality of construction.

Within the city boundaries, the project requires the highest safety standards, including seismic analysis for structural integrity throughout its service life.

Project Requirements

The fast-track project features a typical structure for its Line 1 alignment, where the viaducts support two levels of pathways: the lower one for NH-7 and the upper one for the metro rail.

Impact loading due to train movement was a major concern. Since the stretch is always busy with traffic, a solution was required that would not require revising the existing design. Additionally, minimizing delays to this fast-moving project was critical, a concern shared by all stakeholders, especially the General Consultant (GC), who sought to maintain project agility while ensuring a sustainable solution.

Solution

Dextra introduced Shear Key Bars for the priority section, allowing the structure to neutralize seismic forces. This not only helped the contractor complete the work faster but also enabled the client to conduct the trial run earlier than expected.