On the afternoon of July 23, information from the Hanoi Urban Railway Management Board (MRB) said that the unit and the EPC Contractor Consortium officially deployed the construction of the first fence at Station S3 (Vanh Dai 1 Station) under the Urban Railway Project No. 5, Van Cao - Ngoc Khanh - Lang - Hoa Lac (metro No. 5). This is a milestone marking the project entering the complex underground structure construction phase after completing preparation work.
Station S3 is located at the Nguyen Chi Thanh - Ring Road 1 intersection, is an underground station with a 2-story structure, constructed by open excavation method with a length of about 220m and a width of about 20m.
The surrounding wall is the first item of the underground structure, with a design depth of about 42m, 1m thick, playing the role of the main covering structure, ensuring geological stability, waterproofing and safety for the entire construction process of items more than 18m deep below.


According to MRB, the encirclement wall construction process applies modern hydraulic encirclement wall excavation machine (Diaphragm Wall Trenching Machine) technology, combined with an advanced bentonite solution treatment system to maintain stability of the wall walls. According to the plan, the encirclement wall panels will be deployed in stages, prioritizing completion in the eastern area to soon stabilize the ground.
MRB assesses that underground construction in crowded urban areas is always an item with particularly high technical requirements. Therefore, from the first items, the project determines that construction safety, traffic safety and community safety are priorities throughout the construction process.
The project simultaneously applies many technical solutions to control the soil foundation, protect adjacent works and minimize impact on the surrounding environment. The entire construction area is equipped with a 24/7 monitoring system to continuously monitor parameters such as subsidence, tilt and positioning of adjacent works.
According to MRB, all data is updated in real time for timely handling if abnormalities arise. In addition, foundation reinforcement solutions, equipment load control and strict construction procedures are also being implemented synchronously to ensure the quality of the project and the stability of existing projects throughout the construction process.
The deployment of the first fence at Station S3 is a foundational milestone for the entire underground section of Line No. 5. We are committed to complying with strict technical standards, strictly controlling geological risks to ensure absolute safety for existing works and minimize impact on the lives of people in the area," said Mr. Dang Viet Trung - Deputy Head of Hanoi Urban Railway Management Board.
