Dextra Group | Reliable Connections

San Shek Wan Sewage Treatment Works, Hong Kong

 

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

  1. 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.
  2. 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.
  3. 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.
  4. 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

 

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:

  1. M78/OD75 in Grade CS520 – A total of 60 sets were delivered.
  2. 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.

 

A66 Salzbachtal Bridge, Germany

 

A66 Salzbachtal Bridge, Germany

 
 

The A66 Salzbachtal Bridge, located in Wiesbaden, Hesse, is a 304-meter-long, four-lane motorway bridge on the A66. Originally constructed in the mid-20th century, the bridge has been subject to wear and tear due to increasing traffic loads and aging infrastructure.

Foundation piles are fundamental to the stability and longevity of bridge structures. Ensuring their integrity is crucial to preventing potential structural failures. Dextra played a pivotal role by supplying approximately 10,000 linear meters of Sonitec CSL (Cross Sonic Logging) tubes.

Sonic tubes are essential components in the CSL testing method, which is widely regarded as one of the most reliable techniques for assessing deep foundation integrity. Sonitec, designed for easy installation within the reinforcement cage, facilitates accurate cross-hole sonic logging, allowing engineers to precisely detect and locate defects within the piles.

(Image credit: PORR Deutschland, Wilhelm Schütz)

Cross Island Line (CRL) MRT, Singapore

 

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.

 

Tai Po Railway Pier – Reconstruction of Tai Po Kau Tide Gauge Station

 

Tai Po Railway Pier – Reconstruction of Tai Po Kau Tide Gauge Station, Hong Kong

 

In the dynamic coastal landscape of Tai Po Kau, New Territories, Hong Kong, infrastructure projects demand robust and resilient solutions. One such endeavor, the Reconstruction of Tai Po Kau Tide Gauge Station project, required innovative materials to withstand the unique challenges posed by its environment. Dextra was chosen to provide approximately 1,000 meters of Glass Fibre Reinforced Polymer (GFRP) rebar for the slab of the Tai Po Railway Pier, showcasing the efficacy of advanced composite materials in marine construction.

The Tai Po Kau Tide Gauge Station project aimed to revitalize the existing infrastructure, enhancing its resilience against tidal forces, corrosion, and environmental degradation. Recognizing the limitations of traditional steel reinforcement in marine environments, the project sought alternatives that could offer superior durability and longevity. Dextra’s GFRP rebar emerged as the ideal solution, offering exceptional resistance to corrosion, rust, and chemical degradation commonly associated with saltwater exposure.

GFRP rebar, composed of high-strength glass fibers embedded in a polymer matrix, delivers mechanical properties comparable to steel but with added benefits. Notably, GFRP rebar exhibits significantly lower thermal conductivity, reducing the risk of thermal bridging and enhancing structural integrity in extreme temperature variations. Furthermore, its non-magnetic properties eliminate electromagnetic interference, making it suitable for sensitive applications such as tide gauge stations.

The application of GFRP rebar within the Tai Po Kau Tide Gauge Station project encompassed both straight and bent bars, catering to the diverse structural requirements of the public pier. Dextra’s expertise in custom fabrication ensured precise bending and shaping of the rebar to fit the intricate geometries of the pier structure, facilitating seamless integration and minimizing construction complexities.

Laem Chabang Port

Laem Chabang Port

The Port of Laem Chabang, located on the Gulf of Thailand, is the largest and busiest port in the country, surpassing even Bangkok Port. It is also the 4th busiest port in Southeast Asia. Situated in the Chonburi province, just a couple of hours’ drive from Bangkok and Dextra’s main production facility. The port plays a critical role in the region’s logistics and trade.

Dextra has been involved with the contractor, Italian-Thai, for the engineering and supply of steel structures for the new pier at Laem Chabang Port.

Dextra engineered and supplied its high-performance Marine Tie Bars in Grade 700, the highest grade in our range. This grade offers an improved performance-to-steel ratio compared to lower grades like 355/510 and 500/660. It allows for the use of smaller diameter bars, leading to steel savings, and simplifies logistics and installation efforts.

The bars used in the long tendons were anchored into concrete piles and spliced using turnbuckles and couplers. In total, Dextra supplied 206 tons of Marine Tie Bars for the Laem Chabang expansion project, contributing to the development of this key infrastructure.

Mubarak Al-Kabeer

Mubarak Al-Kabeer

Mubarak Al-Kabeer is a significant seaport located on the island of Bubiyan, east of Kuwait, with an open gateway to the Persian Gulf. This seaport plays a vital role in Kuwait’s maritime infrastructure and economic development.

Dextra was involved in Stage 2 of the first phase of the Mubarak Al-Kabeer construction project between 2011 and 2012, collaborating with Hyundai E&C, the contractor for this ambitious project.

For this large-scale development, Dextra supplied marine tie bars to secure and anchor the quay of the offloading facility. The system leveraged Dextra’s large-diameter M134 tie rods, which were anchored into the combiwalls using Ball Cages, offering a ± 10° rotation capability in all directions, and Captive Nuts, allowing ± 5° rotation capability in all directions.

To accommodate the long tendons, provide the necessary adjustment length, and offer additional flexibility during installation, turnbuckles and Hinge Couplers were integrated into the system where required. These Hinge Couplers allowed for ± 90° vertical adjustment, ensuring that the system was adaptable and could be easily installed under varying conditions.

This solution contributed to the project’s success by providing a durable, flexible, and high-performance anchoring system for the quay, ensuring the stability of the offloading facility for years to come.

Manila International Container Terminal (MICT) – Berth 7

Manila International Container Terminal (MICT) – Berth 7

In 1988, ICTSI secured a 25+25-year concession to operate the Manila International Container Terminal (MICT), one of the Port of Manila’s three terminals. Since then, MICT has grown significantly, increasing its capacity five-fold and becoming the largest and most modern container terminal in the Philippines.

MICT is now globally recognized for its efficiency and modern operations. As part of its expansion, the Berth 7 project was undertaken to alleviate congestion at off-dock container yards by extending Berth 6. Dextra played a key role in this project.

For this expansion, Dextra supplied 110 sets of Marine Tie Bars, each made from Grade 700 steel, with a bar diameter of 85mm. These tie bars were used as anchorages to tie back the main concrete wall, which was cast on top of tubular steel piles. The system was connected to a sheet pile anchor wall, which in turn was linked to the crane rail beam, providing essential stability to the structure.

Dextra’s marine tie bar solution offers three steel grades, with a yield stress of up to 700 MPa, and 22 thread diameters. This wide range ensures that the bars can be precisely matched to meet specific performance requirements, allowing for an efficient and economic use of materials.

By providing high-strength, durable, and reliable marine tie bars, Dextra helped ensure the structural integrity of the expanded berth, supporting MICT’s mission to remain one of the leading container terminals in the world.

Aqaba Container Terminal

Aqaba Container Terminal

The Aqaba Container Terminal (ACT) is located on the northern shores of the Gulf of Aqaba in southern Jordan. It is the only container terminal in the country and the second largest on the Red Sea in terms of capacity.

Dextra contributed to the creation of ACT’s new berth between 2011 and 2012 as part of a project aimed at increasing the terminal’s capacity to 1.2 million TEUs. The expansion began operations in 2013.

For this project, Dextra supplied its Marine Tie Bar solutions to BAM International. The rods were provided in Grade 500 in two sizes: M105 and M125.

The long tendons were connected to the combi-wall on one side with a Dextra Ball Cage, allowing for a multidirectional angle of ±10 degrees. This greatly facilitated the installation process while addressing possible soil settlement.

On the opposite wall, the tie rods were anchored using swivel plates and nuts, set up over waling beams. Dextra’s swivel accessories also allow a rotation angle of ±7 degrees in all directions.

For more information about our marine solutions in the Middle East, please consult our Dubai office.

Port of Douala

Port of Douala

The Port of Douala is a large seaport located on the Atlantic Ocean, in the Wouri department of Cameroon. It serves as the main port of Cameroon and is the busiest port in Central Africa. Through agreements, it also serves countries like Chad and the Central African Republic, which lack direct access to the sea.

To support the ambitious development plan of Port Autonome de Douala, Dextra collaborated with contractor BESIX for the engineering and supply of the steel structures supporting Douala Pier 51, a 165-meter-long quay wall.

In 2015, Dextra engineered and supplied Marine Tie Bar systems with a diameter of M100 and in Grade 700, the highest in our range. Higher grades offer an improved performance-to-steel ratio compared to grades 355/510 and 500/660, allowing for smaller diameter bars, which ultimately provide steel savings and facilitate logistics and installation.

The long tendons were spliced with turnbuckles and couplers. The rods were anchored into the combi walls using Captive Nuts accessories, which allow a multidirectional rotation angle of 5°, easing the installation process.