Launching of Shield Tunnel Boring Machine for First Ever Subway Project in Vietnam
With Mr. Nguyen Thanh Phong, Chairman of Ho Chi Minh City People’s Committee, Mr. Junichi Kawaue, Consul General of Japan in Ho Chi Minh City, and other distinguished guests in attendance, a ceremony was held to mark the launch of a shield tunnel boring machine, which will be used for excavation of two tunnels, as part of package CP1B of the Ho Chi Minh City Urban Railway Project, Line No. 1. This package is responsible for the design and construction of Vietnam’s first subway line, and is being executed by a joint operation between Shimizu Corporation and Maeda Corporation. It is the first time that shield tunneling technology has been deployed in an urban area in Vietnam. Line No.1 will run from Ben Thanh in District 1 in the city centre, to Suoi Tien in the north-eastern part of the city, and will extend for a total distance of 19.7km, including a 2.5km underground section and a 17.2km elevated section. The construction project for Line No.1 is funded by Japan Official Development Assistance (ODA) and is divided into two underground packages and an elevated package, each undertaken by a joint venture led by, or comprised of, Japanese contractors. The 1.74 km-long CP1B package is one of two underground sections, comprising Opera House and Ba Son Stations, and related tunnels. Underground structures in this package, comprise Opera House Station (190m), two shield tunnels (781m), Ba Son Station (240m) and a cut-and-cover tunnel (534m). Construction work on package CP1B commenced in August 2014. Work on Opera House Station involved large-scale excavation, carried out in an urban area with heavy traffic, and in the vicinity of various historic and other significant buildings, many of which had been constructed with shallow foundations, such as the Opera House Building. To protect these buildings, construction of the four-storey, 27m-deep underground station was carefully carried out with detailed analysis and continuous monitoring of ground movement, using a top-down method of construction. Ba Son Station is located adjacent to the Saigon River, inside the old Ba Son shipyard. To facilitate construction works at this location, a double sheet pile cofferdam was constructed in order to prevent water ingress from the river, and to facilitate the construction of a diaphragm wall, bulk excavation works, and construction of the main station structure. The shield tunneling technology will be applied to two east and west-bound tunnels, using a single shield tunnel boring machine. The shield tunnel boring machine will commence its work from Ba Son Station and move towards Opera House Station during construction of the first tunnel. After reaching Opera House Station, the shield tunnel boring machine will be dismantled and transported back to Ba Son Station for assembly and excavation of the second tunnel. The first tunnel work will be completed in September, 2017. The second tunnel work will start in December, 2017 and be completed in May, 2018. The launching of the shield tunnel boring machine is a major project milestone. The joint operation between Shimizu Corporation and Maeda Corporation will continue to ensure high quality and safety during construction, creating important infrastructure, to facilitate the ongoing socio-economic development of Vietnam.