Dự án đường dây 500 kV NMNĐ Nam Định I – Phố Nối

The Nam Dinh I – Pho Noi 500 kV transmission line project helps reduce the load on existing 500 kV lines, ensures N-1 reliability criteria, and transmits power from the North Central region to Northern Vietnam.

The Nam Dinh I – Pho Noi 500 kV transmission line is one of Vietnam’s key national energy infrastructure projects, implemented at an accelerated pace to promptly deliver large power capacity from the North Central region to the main load centers in the North. The project not only relieves congestion and prevents overloading of existing 500 kV lines, but also enhances power supply reliability, meeting the requirements of socio-economic development and national energy security.

In this article, Hanoi Vietnam analyzes the geological characteristics of the Thai Binh area—one of the most critical sections of the route—and introduces the foundation construction solution for transmission line towers executed by our company, utilizing modern equipment and construction methods suitable for weak soil conditions.

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Nội dung bài viết

Geological Characteristics of the Thai Binh Area – A Major Challenge for 500 kV Tower Foundation Construction

The construction area lies within the coastal zone of the Red River Delta, characterized by complex geology, weak soils, and high groundwater levels. Based on field investigations, the soil stratification is as follows:

Layer 1: Clayey silt interbedded with sandy silt, containing organic matter, dark gray in color, in very soft to soft plastic condition. This is an extremely weak layer with low bearing capacity, requiring ground improvement or deep piles extending beyond it.
Layer 2: Clay and silty clay interbedded with clayey silt, locally containing shell fragments, yellow-brown to dark gray, in soft to very soft condition. This layer poses construction difficulties due to borehole instability and reduced load transfer efficiency.
Layer 3: Clay and silty clay, yellow-brown in color, in soft plastic to stiff plastic condition—serving as a transitional layer that may be utilized as an intermediate bearing stratum.
Layer 3a: Fine sand, greenish-gray to light gray, loose to medium dense. This layer provides improved conditions and is suitable for pile toe embedment to ensure bearing capacity.
Layer 4: Clay and silty clay, yellow-brown to greenish-gray, stiff to hard—forming the main load-bearing layer.

This geological structure requires contractors to select equipment with strong penetration capacity and excellent pile stability, while also controlling vibrations to minimize impacts on nearby residential areas.

Construction Solution Selected by Hanoi Vietnam: Efficiency – Safety – Schedule Compliance

After a detailed assessment of subsurface conditions and construction constraints, Hanoi Vietnam Co., Ltd. selected a 50-ton base machine equipped with a 24-meter leader system combined with a DD45 Diesel hammer for tower foundation pile installation.

1. Advantages of the 50-ton Base Machine – DD45 Diesel Hammer Combination

This equipment configuration was chosen for its adaptability to weak soils, capable of handling soft clay and silty sand without causing borehole collapse.

50-ton base machine provides high load capacity and stability during continuous multi-shift operations.
24-meter leader system ensures precise guidance and maintains pile verticality throughout driving.
DD45 Diesel hammer delivers high impact energy, suitable for penetrating stiff clay and medium-dense sand layers, achieving design depth efficiently.

Thanks to this combination, the project was executed on schedule, reducing site preparation time and shortening the construction cycle for each foundation.

2. Optimizing Productivity and Construction Safety

Under weak soil and high groundwater conditions, the construction team:

Utilized temporary casing to stabilize excavations and protect borehole edges.
Applied vibration control measures during hammer operation to minimize impacts on nearby houses and infrastructure.
Continuously monitored elevation and inclination using laser measurement equipment, ensuring deviations ≤1%.
Maintained three continuous work shifts to meet the stringent schedule of the national power transmission project.

Through strict technical and safety management, tower foundations were completed on time with quality fully meeting standards, earning high praise from the project owner and management board.

Significance of the Project for the Northern Power Transmission System

Completion of the Nam Dinh I – Pho Noi 500 kV transmission line enables:

Load reduction and overload prevention for existing 500 kV lines such as Nho Quan – Hiep Hoa and Nam Dinh – Pho Noi.
Additional transmission capacity from power plants in the North Central region—especially gas-fired and coastal wind power—to Northern Vietnam.
Compliance with N-1 reliability criteria, enhancing stability and resilience of the national power grid.
Improved integration capacity for renewable energy sources, contributing to the sustainable development of Vietnam’s energy sector.

The rapid completion progress reflects strong governmental commitment and exceptional efforts by construction units, including the significant contribution of Hanoi Vietnam’s engineering team.

Conclusion

The Nam Dinh I – Pho Noi 500 kV transmission line project is a clear demonstration of the fast, safe, and precise construction capability of Hanoi Vietnam Co., Ltd. under complex geological conditions. With a comprehensive equipment system, extensive experience in weak ground treatment, and large-scale pile construction expertise, we remain committed to supporting key national energy and infrastructure projects across Vietnam.

For further information, please contact:
🌍 Website: https://mayxaydunghanoi.com

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📞 Call: Mr. Dong Sai Gon – +84 842 601 755
📩 Email: hanoi.trandong@gmail.com