Central Kowloon Route (CKR) – Central Tunnel, Hong Kong

Posted on September 11, 2024September 11, 2024 by Kansuda Visesthanakorn

Central Kowloon Route (CKR) – Central Tunnel, Hong Kong

Dextra played a pivotal role in the construction of the Central Kowloon Route (CKR) – Central Tunnel project in Hong Kong by supplying over 60,000 Fortec+ couplers. These mechanical rebar couplers were integral in ensuring strong and reliable connections within the road tunnel structure, meeting the stringent requirements for safety and durability.

The CKR, a major infrastructure project aimed at improving traffic flow across Kowloon, required advanced construction techniques, and Dextra’s Fortec+ couplers contributed significantly to the project’s structural integrity and long-term performance. The couplers were used to connect rebars in various locations, such as precast panels, tunnel access points, and driveways.

Fortec+ is a system that includes an additional rebar preparation process, in which the threaded bar end is proof tested by applying a tensile load. This is a non-destructive test, as the load level remains within the elastic zone of the reinforcing bar.

Image credit: Central Kowloon Route – Highways Department

San Shek Wan Sewage Treatment Works, Hong Kong

Posted on August 2, 2024August 2, 2024 by Kansuda Visesthanakorn

San Shek Wan Sewage Treatment Works, Hong Kong

The San Shek Wan Sewage Treatment Works (STW) project in Hong Kong marks a significant step towards addressing the sewage disposal needs of the South Lantau region. As the population of South Lantau is projected to grow, with an ultimate population reaching approximately 12,600 by 2039, the sewage flow is anticipated to increase to 5,800 m³/day. To accommodate this, a comprehensive sewerage system is being constructed, which includes a trunk sewerage system for Pui O area, a secondary STW at San Shek Wan, and a village sewerage system for Lo Uk.

A critical component of this ambitious infrastructure project is the use of advanced materials and technologies to ensure its successful and sustainable completion. Dextra, a global leader in engineered construction products, has played a pivotal role by supplying Glass Fibre Reinforced Polymer (GFRP) soil nails for the excavation and lateral support (ELS) works.

The Role of GFRP Soil Nails in ELS Works

The excavation and lateral support works are essential to the project’s foundation and stability. The challenging geotechnical conditions in Hong Kong, characterized by complex soil and rock formations, necessitate the use of robust and reliable reinforcement solutions. GFRP soil nails, provided by Dextra, are ideal for such conditions due to their high tensile strength, corrosion resistance, and lightweight nature.

GFRP soil nails are used to stabilize slopes and excavations, preventing landslides and soil erosion. Their corrosion resistance is particularly beneficial in environments exposed to moisture and chemicals, such as sewage treatment works. This ensures a longer lifespan and reduced maintenance costs compared to traditional steel reinforcement.

Benefits of Dextra’s GFRP Solutions

Corrosion Resistance: Unlike steel, GFRP does not corrode when exposed to harsh environmental conditions. This makes it an excellent choice for the wet and chemically aggressive conditions present in sewage treatment works.
High Strength-to-Weight Ratio: GFRP offers a high tensile strength comparable to steel but at a fraction of the weight. This ease of handling and installation translates to time and labor savings.
Durability: The longevity of GFRP soil nails ensures the structural integrity of the excavation and lateral support systems over the extended operational life of the sewage treatment works.
Sustainability: By using GFRP, the project reduces its reliance on steel, thereby contributing to more sustainable construction practices.

Impact on the San Shek Wan STW Project

Dextra’s involvement and the implementation of GFRP soil nails have significantly enhanced the efficiency and sustainability of the San Shek Wan STW project. The advanced materials have ensured that the excavation and lateral support works are not only robust and reliable but also cost-effective over the long term.

Upon completion, the sewage from South Lantau will be conveyed to the newly constructed STW for proper treatment. The treated effluent will then be safely discharged into the sea about 1.4 km off the South Lantau coast, ensuring minimal environmental impact. This project represents a crucial infrastructure upgrade that will support the region’s growth and development while maintaining high environmental and operational standards.

Cairo Monorail Bowstring Bridge, Egypt

Posted on July 5, 2024July 5, 2024 by Kansuda Visesthanakorn

Cairo Monorail Bowstring Bridge, Egypt

The Cairo Monorail Bowstring Bridge project, a pivotal part of Egypt’s expanding urban infrastructure, has significantly benefited from the expertise and quality products supplied by Dextra. Known for their innovative engineering solutions, Dextra provided critical materials to support the construction of this state-of-the-art transportation link.

In particular, Dextra supplied tension rods in two distinct specifications for the project:

M78/OD75 in Grade CS520 – A total of 60 sets were delivered.
M83/OD80 in Grade CS520 – An additional 8 sets were provided.

These tension rods were specifically used as hangers for the bowstring bridge, ensuring a high level of strength and durability, which is crucial for the safety and longevity of the bridge, to maintain structural integrity and withstand the stresses of daily monorail operations.

Dextra’s tension rods, known for their high tensile strength and resistance to environmental factors while providing architectural pleasure, played a critical role in meeting these demands. This involvement underscores the importance of reliable and advanced engineering solutions in modern infrastructure projects, highlighting Dextra’s commitment to excellence and innovation in the field of civil engineering.

Cross Island Line (CRL) MRT, Singapore

Posted on June 12, 2024July 19, 2024 by Kansuda Visesthanakorn

Cross Island Line (CRL) MRT, Singapore

Dextra has played a pivotal role in the construction of Singapore’s Cross Island Line (CRL) MRT project, supplying Glass Fiber Reinforced Polymer (GFRP) soft-eyes, Bartec couplers and Headed Bars for several crucial packages. Dextra continues to support the ongoing packages of this extensive project.

The CRL is set to become Singapore’s eighth MRT line and its longest fully underground line, stretching over 50 kilometers. The project is being executed in three phases, with the first phase anticipated to be operational by 2030.

To minimize the environmental impact on the forested areas of the nature reserve, engineering solutions were meticulously chosen to further mitigate environmental disruption. These solutions include digging deeper into the ground and employing a large diameter boring machine, capable of accommodating two train tracks within a single tunnel. This approach not only reduces the surface footprint but also enhances the efficiency of the tunneling process.

Tunnel Boring Machines (TBMs) are a staple in Singapore’s subterranean infrastructure projects, adept at operating under a variety of ground conditions. The use of GFRP soft-eyes supplied by Dextra is integral to these operations. Soft-eyes are essential components in TBM tunneling, acting as temporary openings that allow the TBM to break through concrete walls without compromising structural integrity. The GFRP material is preferred for its high strength-to-weight ratio, corrosion resistance, and ease of installation, ensuring safe and efficient tunneling operations.

Dextra‘s expertise and reliable supply of GFRP soft-eyes, Bartec couplers and headed bars have significantly contributed to the progress of the CRL project, aligning with Singapore’s commitment to sustainable and innovative infrastructure development. As the CRL project advances, Dextra remains a key partner, supporting the construction of this monumental MRT line that will eventually enhance the daily commute for millions of Singaporeans.

Grand Paris Express

Posted on November 5, 2022March 15, 2024 by Sir Gwi

Grand Paris Express

The Grand Paris Express is a major urban transport project taking place all around the French Capital. The project will add 4 new lines (lines 15, 16, 17 and 18) and extend two existing lines (11 and 14).

Dextra has been involved on the packages of several stations through its local distributor partners. On the line 14 in particular, Dextra supplied Fortec rebar couplers in stations of Orsay and Pont Cardinet.

For the Bagneux Station in the North of Paris, located at the crossing of metro line 4 and future line 15, Dextra supplied its ASTEC Active Anchors.

ASTEC Active Anchors are the preferred solution for subway stations works as Tunnel Boring Machines and earth-moving equipment can simply cut the anchors’ FRP tendons at any stage, eliminating any need of unreliable and costly removal of anchors. The solution was approved for this project by consulting firm SYSTRA.

After numerous successful projects in the Middle East, this was the first time ASTEC Active Anchors (a recent Dextra innovation) were installed in Europe.

Expansion of Sha Tau Kok Sewage Treatment Works Phase 1

Posted on November 4, 2022August 2, 2024 by Sir Gwi

Expansion of Sha Tau Kok Sewage Treatment Works Phase 1

The Sha Tau Kok Sewage Treatment Works Phase 1 Expansion project stands as a testament to Hong Kong’s commitment to environmental sustainability and efficient wastewater management. It aims to increase the treatment capacity, ensuring that the city’s sewage is processed efficiently and in an environmentally responsible manner. A remarkable feature of this expansion is the use of Groutec S couplers to seamlessly link precast columns of the building.

Groutec is designed for the efficient and easy installation of precast concrete elements, reducing construction time and labor costs while providing full structural connection. For this project, Groutec S diameter 32mm precast couplers have been used to connect precast columns in vertical applications. The Groutec coupler is installed in the bottom element, and then grout is poured by gravity directly into the coupler cavity. This process ensures the structural integrity and longevity of the facility.

Doha Metro Msheireb Station

Posted on November 4, 2022March 15, 2024 by Sir Gwi

Doha Metro Msheireb Station

Msheireb Station is the major interchange station of the Doha Metro. Located in Downtown Doha, it connects all of three lines (Red, Green and Gold) and will provide a gateway 2022 FIFA World Cup 2022 stadiums

The Msheireb Station will become one of the largest subway stations in the world by size.

Soft-Eyes for TBMs

For this major project, Dextra engineered and supplied between 2013 and 2015 8 large ASTEC GFRP Soft-Eyes, of a diameter of 8 meters each. Soft Eyes are cages of GFRP rebar, positioned into the D-Walls in-between steel segments. GFRP Soft-Eyes allow Tunnel Boring Machines (TBMs) to go through in a minimum time as the bars can be easily crushed by the tunnel machine.

Tie-Back anchors

To anchor the massive d-walls and prevent any soil displacement during excavation works, Dextra also supplied its ASTEC Active Anchors (AAA). Those innovative post-tensioned GFRP-based anchors, have the benefits of being cut by the Tunnel Boring Machines or standard excavation equipment. Because it can be easily cut, it doesn’t need to be removed from the ground, even when used for temporary applications.

In the case of the Msheireb stations, multi-tendons anchors (10 per anchor on this project) have even been installed in the center of Soft-Eye to anchor the D-Wall. Those anchors were also cut during the tunneling break-through (visible in the video below). In total 150 anchors were installed in the station.

Bangkok BTS

Posted on November 4, 2022March 15, 2024 by Sir Gwi

Bangkok BTS

The Bangkok mass Transit System (BTS) is a large urban skytrain system located across Bangkok, the capital city of Thailand. The system was inaugurated in 1999.

As of 2017, the system consists of 24 elevated stations and 37 km of elevated rail organized in two main lines crossing each other in Siam central station.

The BTS system is undergoing an extension of its two main lines with line segments and stations expected to enter in operations in 2019 and 2020.

Foundations

For various packages over the years, Dextra has supplied Sonitec tubes, which are used to test the concrete pile foundations below stations and rail.

In total, Dextra supplied approximately 40,000 linear meters of Sonitec tubes, a distance actually equivalent ot the BTS system length itself.

Pylons

For pylon vertical bar connections, Dextra offered its
Bartec connection.
Bartec allows to conveniently splice prefabricated rebar cages by the use of a simple rebar coupler, allowing savings in steel compared to overlap and accelerating site operations.

In Thailand the threading operation is supported from Dextra’s factory, conveniently located in the North East of Bankgok. Contractors receive the rebar already prepared and mounted with their rebar coupler.

Madrid Chamartín Clara Campoamor Railway Station Expansion

Posted on November 4, 2022March 15, 2024 by Sir Gwi

Madrid Chamartín Clara Campoamor Railway Station Expansion

Madrid Chamartín Clara Campoamor Railway Station Expansion is one of the largest infrastructure projects in Spain. The expansion project aimed to increase the capacity of the railway station and improve the overall passenger experience. Dextra supplied 60,000 linear meters of Sonitec, a crosshole sonic logging testing tube, for the piling work of the project.

The Madrid Chamartín Clara Campoamor Railway Station is one of the busiest railway stations in Spain, serving more than 60 million passengers each year. The expansion project was necessary to meet the growing demand for train services in the city. The project involved the construction of new platforms, tracks, and passenger facilities.

Dextra, a leading supplier of construction solutions, was chosen to supply the Sonitec crosshole sonic logging testing tube for the piling work of the project. The Sonitec tube is a highly advanced system that enables precise and accurate measurements of pile integrity. The system uses crosshole sonic logging technology to assess the condition of the piles, ensuring that they are strong enough to support the weight of the railway station.

The use of the Sonitec crosshole sonic logging testing tube allowed the construction team to carry out the piling work with confidence and ensured the structural integrity of the piles. The system provided real-time data on the pile condition, enabling the construction team to make informed decisions and make any necessary adjustments during the construction process.

Banner image credit: UNStudio, b720 Arquitectura and Esteyco

Melbourne Metro

Posted on November 4, 2022March 14, 2024 by Sir Gwi

Melbourne Metro: five new underground stations

The Melbourne city’s metropolitan rail service operates 226 six-carriage trains across 998 km of tracks. The Metro has 15 lines and 222 stations, serving more than 400,000 passengers a day across the city.

In 2017, the construction of a 9 km long tunnel and five new underground stations were announced for greater capacity and additional coverage of the suburban area of the city.

The construction started in 2018. Dextra was involved in the project by supplying rebar connectors with fully automated rebar preparation equipment for the stations’ structure reinforcement works.

Griptec couplers were chosen thanks to the unrivaled performance in tension, compression and fatigue, and 400,000 units have been delivered.

Moreover, Dextra also supplied:

5,300 GFRP Astec Combination Bolts. It is used at the CBD cavern location. The 19m width of the cavern allowed for the construction of two conventional 7m tunnels, built in parallel with the middle segments secured by GFRP CB Bolts, that can be cut to make the gallery wider.

2,400 GFRP Geotec GR45 – 25mm dowels of 11.8 meters long were used to secure the face during the excavation.

900 GFRP Astec soil nails ST50 – 41 were applied to secure several stations under construction. Some of them are outside of the boundary of the project since the GFRP can remain on the ground outside of their property and can easily be cut later.

16 soft eyes were used in d-wall and bored pile of five stations.

Dextra was able to support and share their expertise on GFRP at design stage and produce the GFRP shaped solutions as per the owner expectation. Thanks to the cuttability of the GFRP, the TBM can pass through the d-wall in a limited time without any damages.

The Metro tunnel and its new stations are due to open in 2025 and predicted to be a new landmark of the city.

(photo credit: Hugh Llewelyn at https://bit.ly/2S0kbAG)

Category: Rails, Metro and Tunnels