The first section of the Thu Thiem Tunnel was towed on the Saigon River to its immersion position at Bach Dang Wharf in Ho Chi Minh City’s District 1 Sunday for Monday’s installation.
The tunnel, which will link inner District 1 to Thu Thiem Area in District 2, consists of four giant tunnel concrete sections made at a casting station in neighboring Dong Nai Province's Nhon Trach District.
At 7:40 am Sunday, HCM City vice chairman Nguyen Thanh Tai launched an order for the towing of the first section, which weighs about 27,000 tons, at the casting station. The moment was witnessed by Construction Minister Nguyen Hong Quan, Transportation Minister Ho Nghia Dung, and other city leaders.
The first is 92 meter long, 33 m wide and 9 m high. With a segment of 22km of waterway running from the casting station to District 1 on the Saigon River, four tugboats towed the module afloat on the water surface.
At about 1 pm, the module was put into its place at Bach Dang Wharf.
Hundreds of city dwellers gathered at the wharf and Tan Thuan Bridge also over the river to watch the towing and positioning process.
All vessels are being banned from traveling on the river from 7am Sunday to midnight on Monday, March 8.
The construction of the Thu Thiem Tunnel, which is part of the East-West Highway and Water Environment Project, is expected to be completed next year. It will be Vietnam’s first under-river tunnel.
The site where the modules will be installed has been dredged to the depth of 12 to 13 meters, with an estimated volume of 450,000 cu. m of mud.
The contractor, Japan’s Obayashi Corporation, will pump water into the module with the two ends covered by steel to gradually lower it into the riverbed.
Global positioning systems will be used as a tool to position the module on its location.
After being located on the site, the contractor will release the water and pump concrete inside it to keep it from floating.
At the same time, a layer of sand will be pumped beneath the module and the contractor will cover its top with a 3-metre layer of sand.
Two positioning rods, 26m high, will be attached to the concrete section for workers to be able to find it during installation.
The other three sections will be towed and installed in April, May and June. The four sections of the tunnel will be connected in August.
