The construction site of Đèo Ngang Tunnel. VNA/VNS Photo

HÀ TĨNH – The Đèo Ngang Tunnel expansion project is being executed around the clock to accelerate progress, with the aim of finishing by the end of this year.

Contractors working on the Đèo Ngang Tunnel expansion project, a 650m-long tunnel through the Hoành Sơn mountain range, are making efforts day and night to meet the deadline.

According to Lại Xuân Khoa, head of the safety division at Sông Đà 10 company, the final blasting was conducted last week to remove the last remaining rock masses, officially completing tunnel excavation through the Hoành Sơn range.

“Excavation was completed one month ahead of schedule, allowing for smoother logistics, as materials and equipment can now be transported directly through the tunnel instead of taking a detour,” said Khoa.

“This contributes to faster progress and supports our goal of bringing the project into operation by the end of the year.”

Immediately afterwards, workers from Sông Đà 10 company began pouring concrete segments for the tunnel structure, which spans 555m.

A total of 120 workers and engineers along with more than 40 machines have been mobilised to construct 57 tunnel segments, aiming to complete one concrete segment every two days.

Khoa added: “Sông Đà 10 company has the capability and experience in constructing hydropower plant tunnels, which are more technically demanding than road tunnels.

"Therefore, when assigned this project, company leadership instructed workers to make the most of each day to accelerate progress and reach completion by year-end.”

Regarding challenges, Khoa said that the project faced a two-month delay in site clearance on the southern side of the tunnel.

Once the land was handed over, workers acted in line with the Prime Minister’s directive to work day and night to make up for lost time.

In addition, the construction project must also carefully calculate the issue of power grid safety as right on top of the tunnel are two 500kV lines and the blasting process to expand the tunnel must also ensure safety, avoiding incidents in the operation and exploitation of the current tunnel.

As the contractor in charge of constructing the two bridges connected to the Đèo Ngang Tunnel expansion, Phạm Văn Tuấn, technical officer at Long Hưng Construction Company, said the Đồng Bò Bridge with length of 171.1m and Đồng Mười Bridge, 43.2m, have been under construction since mid-March and are currently at the pier and girder installation stage.

“The bridges and approach roads are progressing as planned. The contractor commits to completing them in parallel with the new Đèo Ngang tunnel so that everything can enter operation by year-end,” Tuấn said.

The Đèo Ngang Tunnel expansion began construction in January with a total investment of VNĐ219 billion (US$8.6 million), targeting completion and operation by year-end.

The tunnel is 650m long, with a 555m structural section, 10.5m wide and designed for two lanes of traffic with a speed limit of 80km per hour.

The tunnel traverses the Hoành Sơn mountain range, connecting Hoành Sơn Ward of Hà Tĩnh Province and Phú Trạch Commune of Quảng Trị Province.

Upon completion, National Highway 1 will feature two tunnel tubes and four traffic lanes, reducing pressure on the existing tunnel and improving traffic flow along the North–South route. VNS