On the morning of June 8, 2025, in Quang Binh province, tunnel 1 of Package XL01 which is a project to improve the railway line through Khe Net pass, was officially bored through. This is one of two key tunnel components of the project, which was carried out by the ILSUNG-DEOCA contractor consortium. The breakthrough marks a significant milestone after more than 16 months of continuous work under challenging geological conditions.

The ceremony was attended by local leaders, investors, contractor consortium, consulting consortium, as well as engineers, technicians, and workers from the package.

Delegates performed the tunnel breakthrough activation ceremony.

According to a report from the Package’s Management Board, the contractor consortium has currently mobilized over 250 staff members, engineers, and workers, along with 30 specialized pieces of equipment. They have organized 4 simultaneous construction fronts, operating in "three shifts, four crews," in line with the Prime Minister's directive.

Tunnel 1 is 580m long and runs through Huong Hoa commune in Tuyen Hoa district, Quang Binh province. During construction, the area encountered many weak geological layers such as completely weathered limestone, water-saturated clay, and fractured rock. There are also a number of karst caves and constant streams of groundwater running across the tunnel face.

Immediately after the north portal was opened, the tunnel's crown shifted due to the weak geological condition. This forced the contractor to implement additional reinforcement solutions, which were not in the original design, to proceed with safe excavation. The south of tunnel 1 revealed an extremely complex geological structure with completely weathered rock, loose soil and stone, and groundwater flowing continuously along the anchors and ribs, which increased the risk of the tunnel face becoming unstable during construction.

Tunnel 1, which is a part of Package XL01 under a project to improve the railway line through Khe Net pass, was officially bored through.

To ensure safety and progress in these complex geological conditions, the contractor proactively adjusted its construction methods, divided into smaller cross-sections and excavated in half-sections, using a combination of shotcrete and high-strength concrete to reinforce the tunnel face. The team's flexible response to the difficult geology, along with close coordination between the construction fronts, helped maintain a steady pace of construction that aligned with the project's timeline.

Previously, in October 2024, tunnel 2, which is 355m long (located in Kim Hoa commune) was excavated two months ahead of schedule. Tunnel 2 is now in its final construction phase, with the entire concrete lining expected to be finished before June 15, 2025.

“We see this not only as a construction task but as a comprehensive test of our organizational ability, technical mastery in tunneling techniques, and our flexibility in the face of unpredictable geology. Today’s breakthrough ceremony is an important milestone that facilitates the transport of fuel, materials, equipment, and manpower, and paves the way to accelerate overall project progress,” Mr. Nguyen Duy Song, Deputy Director of the Package’s Management Board, said.

Tunnel 2 is now in the final stage of construction.

The Khe Net railway tunnel is being built using “DEOCA’s system” NATM technology, which has been successfully applied to many large-scale tunnel projects across the country.

“The project faced many difficulties because the actual geological conditions were very different from the original design. However, the contractor consortium promptly discussed and agreed to find suitable solutions, ensuring safe construction that meets quality and schedule requirements. I value DEOCA Group as a highly experienced company in infrastructure construction. Our consortium has coordinated effectively with the Railway Project Management Board and the consulting firms,” Mr. Moon Jong Ki, General Director of Ilsung Vietnam Co., Ltd., (representative of the contractor consortium), shared.

According to the plan, the entire XL01 package will be completed in December 2025. Alongside construction, a priority is placed on ensuring workplace safety and environmental protection. Monthly training sessions are held on-site to improve discipline and reinforce safe tunneling methods. The training program also includes fire prevention and emergency response.

In the next phase, the Management Board will focus on accelerating the completion of tunnel 2 and implementing other technical elements, such as waterproofing, finishing the drainage system, and installing ventilation and lighting equipment. All work will be closely monitored by an international consulting firm to ensure absolute quality and safety.

News: Chi Lam - Photo: Tuan Linh