The Noi Bai - Lao Cai expressway expansion project is invested by Vietnam Expressway Development Investment Corporation, with a total investment of nearly 7,700 billion VND.
According to the design, the project will expand the scale from 2 to 4 lanes with a cross-section of 24m, add a median strip, build more bridges, extend the underpass and complete the synchronous traffic safety system.
In which, the 530m long Dai Viet tunnel through Lao Cai province is considered a key item, deciding the progress of the entire project.
In mid-May days, in hot weather, the tunnel entrance area is always covered with rock dust and the sound of drilling machines echoes.
Under the subsidence heat from the cliffs, workers are still continuously operating excavators, drills, reinforcing tunnel arches, and spraying concrete to prevent landslides.
Each drill bit resounds continuously day and night in the heart of the mountain. Each meter of tunnel dug is the result of a tightly coordinated chain from drilling, blasting, excavating, transporting soil and rocks to spraying concrete and installing support structures.
Mr. Nguyen Van Hung - a worker in the tunnel drilling team - said that there are working shifts lasting many hours in a hot and humid environment, thick rock dust and continuous roar of machinery.
Working in the tunnel is very hot and suffocating, clothes are always soaked in sweat. Some days working through the night until morning, people are very tired, but looking at each meter of the tunnel being extended, brothers have more motivation," Mr. Hung expressed.
Mr. Phung Duc Tue - Construction site commander of Song Da Company 10.1 said that the unit maintains continuous construction, almost no days off to compensate for progress and ensure the tunnel opening plan on schedule.
“Construction conditions in the mountains are complex, prolonged hot weather increases labor intensity. We have to arrange flexible shifts, increase ventilation fans, drinking water, and protective equipment to ensure workers' health,” Mr. Tue said.
According to Mr. Tue, technical work is strictly controlled in each stage. After each blasting and explosion, technical teams must carefully check the geological status and stability of the tunnel wall before deploying excavation and reinforcement.
Mr. Tran Ngoc Hai - Deputy Director of the Northern Expressway Project Management Board (Vietnam Expressway Development Investment Corporation) - said that contractors are accelerating construction simultaneously on the entire route to ensure the goal of completing the project by the end of 2026.
The biggest difficulty currently is the complex mountainous terrain, erratic weather and pressure to both construct and ensure traffic on the expressway being operated. However, the units still maintain stable progress, especially the mountain tunnel item," Mr. Hai informed.
After more than 6 months of implementation, the project has reached over 40% of the construction volume. On the entire route, the shape of the 4-lane road is gradually becoming clear. Many sections of the roadbed have been paved with the first asphalt layer; bridges, taluy, culverts, and drainage ditches are also being urgently completed.
Dai Viet tunnel alone has been dug about 475m on a total length of 530m so far, approaching the time of technical tunnel opening. Construction teams are being strengthened with manpower and equipment to complete the last meters of the tunnel.
