To prepare conditions for the Nhon - Hanoi railway station tunnel boring machine to operate at the end of July 2024, the Hanoi Urban Railway Project Management Board (MRB) is increasing the transportation of tunnel lining concrete slabs. especially from the factory in Ha Nam to station S9 (Kim Ma, Hanoi).
Information from MRB, with a tunnel length of more than 4km, the project must produce 3,488 tunnel rounds. In terms of size, the tunnel shell is a universal type, consisting of 6 pieces with an inner diameter of 5.7m, an outer diameter of 6.3m, a ring width of 1.5m and a shell thickness of 0.3m, weighing 4 ton.
The tunnel shell is prefabricated at the factory, then transported to the project site to be placed in the chamber containing the TBM machines. When the TBM tunneling machine operates and digs up the soil, the tunnel lining will be completed.
According to the leader of the tunnel lining production unit, raw materials for production include: Cement, steel reinforcement, aggregates (stone, sand), water, additives and tunnel lining accessories.
After the preparation process, concrete is mixed by an automatic mixing plant according to the determined mixing ratio, then poured into reinforced molds, using vibration compaction techniques to remove air bubbles and Make sure the concrete is evenly distributed.
Next, the tunnel lining panels will be covered with closed chambers to perform steam curing work until the concrete of the tunnel lining panels reaches 60% of the prescribed compressive strength, in the range of 4 - 6 language.
"Completing the above stages, the tunnel shell panels will be moved to the water maintenance area within 7 days. Finally, the product will be moved to the storage area. Here, the product is painted with a protective layer. epoxy protection, marking each tunnel segment to serve installation and construction", the leader of the tunnel lining production unit shared.
It is known that to date, the factory has produced more than 800 rounds out of a total of 3,488 tunnel lining rounds of the project. From the night of July 19, the first tunnel shells were transported to Hanoi.
Regarding the progress of tunneling, Mr. Nguyen Ba Son - Deputy Head of Hanoi Urban Railway Management Board said that currently, experts are conducting the final inspection to proceed with tunneling, expected to start from July 30.
"Tunnel drilling will take place within 15 months. To minimize the pressure impact, 2 machines will drill staggered. Every day, 10m to 12m will be drilled. Households are identified to be affected during the process. The tunneling process has now begun to relocate.", Mr. Nguyen Ba Son said.
At the second meeting of the Working Group to assist the Steering Committee in implementing urban railway projects in Hanoi and Ho Chi Minh City, which took place on the morning of July 17, Vice Chairman of Hanoi People's Committee Duong Duc Tuan said that currently Hanoi has Test operation of the elevated section of the Nhon - Hanoi station metro project , expected to be in commercial operation at the end of July.
