The 27,000-tonne structure will be settled in the river bed on March 9 morning, while the other three segments will be towed to the site later from Nhon Trach District in southern Dong Nai province.

The 370.8-metre long underwater tunnel will connect the city’s District 1 with the new urban Thu Thiem Area in District 2. The tunnel is designed to ease the east-west traffic flow in the city.

Experts said the sealed segment will be lowered into a prepared trench on the riverbed and then covered with backfilling material in order to secure its position and protect the tunnel.

The installation of each unit takes about one month to complete.

After the four units are secured and connected with the tunnel entrances at both ends, the driveway and emergency pathways will be paved and assorted installation projects will continue until the tunnel is completely open in mid-2011.

The tunnel is part of the Sai Gon East-West Highway Project that is being implemented by HCM City with financial assistance from the Japan International Cooperation Agency (JICA). The agency has provided JPY41.027 billion (US$456 million) in ODA for the project.

Addressing a press meeting on March 7 afternoon, Tsuno Motonori, chief representative of JICA Vietnam Office, said this was the first infrastructure project supported by JICA in HCM City.

This new six-lane, 22-km road will connect National Highway 1A with the Hanoi highway in the east. The road will also pass under the Sai Gon River through the Thu Thiem tunnel.

The western part of the highway was open to traffic on September 2 last year.

Four bridges over the canal-Khanh Hoi, Calmette, Chu Y, and Cha Va-were also open to traffic last year.

The road section on the Thu Thiem side will be gradually open in April this year.

Motonori said the installation of the immersed tunnel units is the most difficult part of the EWH project. He added that these are the first immersed tunnels in Vietnam and also the first project of this type in Southeast Asia.

According to JICA’s figures, the agency has also provided ODA loans of US$267 million to the HCM City Water Environment Improvement Project, US$232 million to the City Urban Railway Construction Project’s Ben Thanh Suoi Tien Section, US$253 million to the Tan Son Nhat International Airport Terminal Construction project, and US$185 million to the HCM City-Long Thanh-Dau Giay section of the North-South Express Construction Project.