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HCMC Metro Line 1: Ba Son Shipyard Station

HCMC Metro Line 1: Ba Son Shipyard Station

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

There will be eight lines in the metro system. The first, second, and fifth lines are in the implementation stage, while the remaining lines are in the investment planning stage.

The project’s Line 1 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 throughout the underground section. Line 1 also includes a Saigon River crossing.

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

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

Mae Fah Luang Chiang Rai Airport Renovation & Expansion

Mae Fah Luang Chiang Rai Airport Renovation & Expansion

Mae Fah Luang Chiang Rai Airport, located in Chiang Rai, Thailand, is a vital transportation hub for the region. The airport serves as a gateway to the popular tourist destinations of Chiang Mai, Chiang Rai, and the Golden Triangle. In recent years, the airport has undergone a major renovation and expansion project to modernize its facilities and increase its capacity. As part of this project, Dextra supplied over 180 tons of dowel bars to be used as construction joints for the airport runway pavement.

The construction of a runway pavement requires a significant amount of planning and preparation. One of the essential components of a runway pavement is the construction joint, which connects the individual concrete slabs together. Construction joints are necessary to ensure that the pavement can withstand the heavy loads of aircraft and the extreme weather conditions. Without proper construction joints, the pavement can experience cracking, spalling, and other types of damage.

Dowel bars are a critical component of construction joints, as they provide load transfer between the individual concrete slabs. Dowel bars are typically made of steel and are placed in the pavement perpendicular to the construction joint. They allow for movement between the concrete slabs while providing support and load transfer.

For the Mae Fah Luang Chiang Rai Airport project, Dextra supplied over 35,000 dowel bars, totaling more than 180 tons of steel. The dowel bars were manufactured at Dextra’s facility in Thailand and were delivered to the construction site in stages to meet the project’s timeline.

The project has not only increased the airport’s capacity but also provided a safer and more reliable transportation hub for the region.

Río Subterráneo a Lomas Tunnel

Río Subterráneo a Lomas Tunnel

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 Bernal’s Quilmes area to the city of Lomas de Zamora.

Being 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 last 40 years. This new system will provide 2.5 million inhabitants in the Buenos Aires metropolitan area’s southern region access to freshwater.

For this significant project, Dextra supplied soft eyes reinforced with GFRP (Glass Fiber Reinforced Polymer) bars to facilitate the penetration of Tunnel Boring Machines (TBM) through a reinforcement cage.

The project required two boring machines to be launched and received from shafts. The tunnel was excavated at an average depth of 25 meters, starting with a curve with a radius of about 400 meters, and moving along a largely straight alignment, with a maximum slope of +/- 2 percent.

The first launch shaft is composed by 4 circular sectors that interconnected with each other in the bottom area. The total length of the shaft is around 45 meters long, 12 meters wide, and 25 meters high.

The whole project is anticipated to take approximately 10 years to complete.

Dubai Metro

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

Coimbra B-Portagem Mondego Metro

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

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

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

London Crossrail

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 for 50 years.

The project consists in a 118-km east-west rail link across Greater London which will run 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-Wall (vertical and horizontal connections), columns and piles (vertical connections).

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

Panama Metro Linea 1 & Linea 2

Panama Metro Linea 1 & Linea 2

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

Panama metro Line 1 first line started being built in 2010 and started operating in 2014. It is 16km long with part of the line undergroup, and part elevated.

Following the success of the first line, a second line has now entered construction phase and should start operation by the end of 2018.

Pier columns For this large construction project, Dextra has been involved between 2011 and 2012 (linea 1) and since 2015 (linea 2) for the structural reinforcement of the large pier columns in the elevated packages of the line.

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

To perform that application, cages are prefabricated together on the ground before being split by unscrewing couplers all on the same side. The cages are then transported to site.

Once lifted and put on top of each other, with the same bars matching the one they previously splice, the cage reconnection can then be made with the use of a standard
Bartec couplers.

Singapore MRT Downtown Line

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

Chennai Metro

Chennai Metro is a urban transport system in the city of Chennai, large fast developing city in the South of India. The system comprises 4 lines, part underground and part elevated, and a total of 42 stations. Construction started in 2009 with the first line opening to the public in 2015. Total length of the system planned exceeds 45.1km.

Underground stations For this large construction project, Dextra has been involved between 2011 and 2015 in the design, engineering and supply of 61 FRP Soft Eyes for stations 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 a minimum time, saving time on 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 are connecting 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 Chennai metro, Dextra also supplied the corrosion accessories necessary for this type of permanent applications.

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 one the station is excavated, with second phase rebar being reconnected to start the slabs.

Rio Metro Line 4

Rio Metro Line 4

The Rio de Janeiro Line 4 is a subway line. It is part elevated and part underground (2 segments). The line has been planned to open for the 2016 Rio de Janeiro Summer Olympics.

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

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. The time factor is especially important in humid environments such as Rio to limit the water entry into the station excavations.

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

Couplers were also used horizontally to provide a reconnection point for slabs (at station level and at the surface) in the D-Walls.

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