Thu Thiem Tunnel soaked spots at permissible levels

Soaked spots and moisture found in the first two sections of the Thu Thiem Tunnel are not serious and will not affect the quality or completion of the work currently under construction beneath the Saigon River in Ho Chi Minh City. 

A soaked spot is covered with black paint in the second section of Thu Thiem Tunnel (Photo: VnExpress)

Oriental Consultants, the consulting supervisor for the project, made the statement at a meeting on May 25 with city leaders, including the city People’s Committee chairman Le Hoang Quan and permanent deputy chairman Le Thanh Tai, to seek solutions to the situation.

According to the Oriental Consultant Company, the soaked spots, measured at 2ml/hour/m2 are within the permissible levels, which extend up to 5ml/hour/m2.

The company earlier reported the city People’s Committee that there are 130 soaked and wet spots inside the tunnel’s first two sections.

Accordingly, builders installed a host of equipment to the tunnel ceiling, including anchored bolts, used to connect cables with the tunnel section to fasten them to the riverbed.

The consulter said that spaces between concrete and the bolts as well as and piping, installed to blow sand to under the tunnel bottom to keep the tunnel fixed in future, have contributed in causing the seeping moisture.

The Oriental Consultant divided the issue into three levels. First level is humidity, in which the tunnel inside is wet making the concrete surface change its color. Second level is soakage, in which moisture is visible and wet to the touch.
The third level is leakage, in which concrete changes color and water drips down the tunnel walls.

After examining wetness within the tunnel on April 27, the company explained that the soaked spots did not constitute leakage.

Specifically, the first section had three wet spots in the bottom, over 30 wet and soaked spots in the ceiling and in 13 locations along the tunnel walls.

The worse conditions are in the second section of tunnel, which as three wet spots along the tunnel floor, and over 50 and 30 soaked and wet spots in the section’s ceiling and walls respectively.

Most of the moisture is located along the tunnel’s joints.

To prove that the soaked spots are not serious, the company said that the soaked condition had already decreased 50 percent in the one month since the first section’s installation into the riverbed.

The company pledged to ensure the quality of the work.

Luong Minh Phuc, director of East-West Highway management board also said that the soaked conditions are within permitted levels and all technical problems have been reported to the State Inspection Council.

To handle the soaked and wet spots inside Thu Thiem Tunnel, the work contractor would continue observing conditions, while Oriental Consultant would continue studying reasons and seek out measures to resolve the problem.

Thu Thiem Tunnel is the first river tunnel in Vietnam. It is part of the East-West Highway project in HCM City and will be the longest river tunnel in Southeast Asia.

The tunnel will link HCMC’s Districts 1 and 2 is slated to open to traffic next year, allowing vehicles to travel at 60 kilometers per hour.

By Q.Hung – Translated by Hai Mien

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