Bai Gio railway tunnel expected to open to traffic on April 22

Contractors are urgently drilling geology, reinforcing Bai Gio tunnel, clearing rocks and soil, with plans to complete on April 22 to open the North-South train route.

On the morning of April 16, Deputy Minister of Transport Nguyen Danh Huy held an online meeting with the on-site working group to discuss a plan to overcome the landslide incident at Bai Gio railway tunnel in Khanh Hoa province.

The representative of the field working group said that the survey showed that the landslide material contained rocks of various sizes and strongly weathered rocks in the form of sandstone and gravel. Currently, large rocks have completely filled the tunnel dome with a volume of about 150 m3. The geology of the tunnel top is in the form of stacked rocks, intertwined, creating large voids.

With the principle of maintaining stability above and inside the tunnel, on April 15, the contractor reinforced the collapsed rock mass in the tunnel by placing anchors to create cells to inject cement mortar to solidify the loose rock mass and create a hard skeleton. At the top of the mountain, at the location of the collapsed tunnel, the contractor drilled geological exploration to inject cement mortar, filling the collapsed void, to stabilize the rock mass.

On April 15, the contractor drilled two holes on the mountain, one 23 m deep (reaching the roof of the tunnel), the other about 18 m, then used a concrete pump to pump in. Photo: Bui Toan

Today, the construction unit prepares anchor drilling equipment, high pressure grouting machine, mixing station, anchors... to drill anchors into the mouth of the sinkhole and pump high pressure grout to create stable adhesion. Then the workers will gradually dig up the collapsed soil and rock in the tunnel, installing the support frame as they dig.

After installing all the support frames in place, the contractor will spray mortar and concrete the tunnel lining. It is expected that on April 22, the units will complete the treatment to open the North-South train route.

To fix the problem, Song Da 10 contractor mobilized 20 staff, workers and a line of construction equipment and machinery. Construction Investment and Construction Joint Stock Company 3 has about 80 workers. Phu Khanh Railway Joint Stock Company - the unit managing the railway section through Khanh Hoa, sent about 250 people to the construction site.

According to Mr. Dang Sy Manh, Chairman of the Board of Directors of Vietnam Railway Corporation , the landslide at Bai Gio tunnel forced the industry to transfer an average of 10 trains per day. By the evening of April 15, the units had transferred more than 13,000 passengers on 38 trains from Tuy Hoa station (Phu Yen) to Gia station (Khanh Hoa) and vice versa.

77 freight trains were blocked. The railway industry had to negotiate with the shippers to transfer the goods, and has so far transferred 16 trains through the incident area, prioritizing fresh, frozen and express goods.

Mr. Manh assessed that the Bai Gio tunnel incident caused great damage to railway transport. The Corporation proposed that all levels consider funding sources to minimize damage, and that localities arrange transport vehicles and exempt road use fees for vehicles transporting passengers and goods through Deo Ca tunnel.

After fixing the Bai Gio tunnel collapse, the competent authority needs to consider allocating capital to reinforce the first step of 12 weak tunnels on the North-South route with an estimated cost of 500 billion VND, and have a plan to handle 27 weak tunnels on the entire railway line.

At the meeting, Deputy Minister Nguyen Danh Huy assessed that Bai Gio tunnel has very complex geology, was built a long time ago, its structure has degraded and the possibility of landslides is in the forecast of the State management agency since 2020.

The handling is carried out according to the "4 on-site" principle, ensuring 5 requirements: earliest route opening, fastest mobilization of forces, most creative solutions, absolute safety, units concentrating the highest resources to construct 24/24 hours, in accordance with the Prime Minister's direction. The working group of the Ministry of Transport will hold daily meetings with units at the site to grasp the construction progress and provide timely instructions.

Bai Gio Tunnel is over 400 m long, 5 m high, 4 m wide, and about 900 m long, located in Dai Lanh commune, Van Ninh district, Khanh Hoa province. The project is being reinforced and renovated under package 11A, a project to reinforce weak tunnels, open new stations, and renovate the upper-floor architecture of the Vinh - Nha Trang section. Project Management Board 85 - Ministry of Transport is the investor.

At noon on April 12, while the contractor was demolishing the old concrete tunnel lining, the tunnel arch collapsed, disrupting train operations.

Mr. Duy

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