Japanese contractor starts fixing cracks on river tunnel

The news was confirmed on Monday (15 June 2009) by the East-West Highway and HCMC Water Environment Project Management Unit, who said the contractor would use epoxy glue to fix the cracks after the solution won approval from the city government.

Vuong Hoang Thanh, Deputy Director of the Project Management Unit, said the repair was to be completed in the next two months and the contractor would start installing the four sections pre-constructed for the Thu Thiem Tunnel in early 2010.

Last June, after the contractor completed casting four tunnel sections in Nhon Trach City of Dong Nai Province, relevant authorities found cracks that developed in the tunnel sections. Each section measures nine meters high, 33 meters wide and 92 meters long, and weighs some 25,000 tons.

Agencies under the Ministry of Construction had inspected the faulty sections to gauge the impact on the quality of the overall project. The biggest crack has a width of between 0.2mm and 0.3mm stretching some two meters.

They also found that cracks had absorbed rainwater, which would weaken the loading capacity and stability of the whole tunnel structure, said inspectors.

Last November, the HCMC government named Australia’s company Connell Wagner as the consultant to investigate the cause of the cracks in the four tunnel sections and to suggest solutions to the problem.

The city has used its budget to pay in advance VND16 billion for the Australian consultant to help fix several cracks in a major tunnel section. The contractor Obayashi must reimburse this sum as well as all the repair costs.

Connell Wagner in a report said the cracks mainly resulted from segregation of concrete, a high dust concentration that affected the cement’s adherence properties and the concrete’s compression.

The consultant proposed using a special glue to fix those cracks. As the project owner, the HCMC government has approved the proposed solution.

Luu Quang Hung, head of the State Appraisal Committee for Construction Projects, last August told reporters at a press briefing in Hanoi that “all are under control” as the project was regularly inspected by the committee.

According to the project management unit, construction at two approach roads of the tunnel in District 1 and District 2 has been completed. The contractor will tug four pre-constructed tunnel sections from Dong Nai Province to the construction site early next year as scheduled. It will take 20 days for tugging each section along the Saigon River to the site.

The 1.5-kilometer-long tunnel, including a 370 meters under the riverbed, was constructed in 2005 as the most important package of the East-West Highway project. The management unit also said the tunnel will open for traffic in late 2010.

The East-West Highway once in place will be a 22-kilometer road from the eastern part of the city to the south, running through districts 1, 2, 4, 5, 6, 8, Binh Tan and Binh Chanh.

As planned, the first stage of the project, with the road stretching from National Highway 1A in Binh Chanh District to the Calmette Bridge in District 1, will open to traffic in September.

The project costs nearly VND9.9 trillion and almost two-thirds of the capital is funded by the Japan Bank for International Cooperation (JBIC). By the end of 2007, the central Government and the project’s donor agreed to extend the loan from January 17, 2008 to March 17, 2012. The highway project had faced many difficulties including prolonged site clearance and redesigned bridge plans.