The application of steel sheet pile cofferdam in the tunnel project of China

Today let’s talk about the application of sheet pile cofferdam in the project Shuiguohu Tunnel in Huhan, China. “Shuiguohu Tunnel” is so named because it is located at the east of “Shuanghu” bridge over the Shuiguo Lake (“Lake” in chinese is called “hu”). South to the front gate of Hubei Audit Office, north to Hubei Consumer Association on Donghu Road, the 1735m long tunnel is the longest subaqueous tunnel in the city of Huhan and one of important nodes in the city’s municipal infrastructure project. It is designed as a four-way bi-directional tunnel. Using the new method of steel sheet pile cofferdam and steel sheet pile cut and cover construction , the total investment of the project is 537 million RMB and also includes the main structure of the tunnel engineering, and mechanical and electrical equipment installation, tunnel decoration, fire, surveillance, transportation, lighting and other ancillary works. Currently, The west tunnel connecting East Lake Road and the North Luoshi Road has been open to traffic as a trial operation. Under the command of the traffic police, the vehicles goes smoothly through the tunnel. It is reported that the opening of the West line of the tunnel is expected to reduce the two-third of the bridge’s traffic.

The difficulty of the sheet pile cofferdam

At the 621 meters long middle part of the tunnel , the original construction plan was divided into “three sections building way” —— build three cofferdams, pump out water, and dug a tunnel. The reason is two gates, which are under the bridge and near the culvert of a harbor nearby must not be “closed.” Only in 3 section building way can we ensure the two gates are always through.

But it takes more than 26 months for the “3 section plan”. The whole project will run out of time by this way! Leadership of the project in Huhan Municipal Infrastructure Group is busy seeking for a “faster” plan by constantly consulting experts from Water Industry and Water Department of China.

By the in-depth study and investigation on the East Lake’s hydrological and geological data and contacting experts about the rainfall and drainage situation in this area, the technical experts on the tunnel project learned that every year October to next April is the dry season in Wuhan. When the water level of the Lake drops, the two gates is actually “Disconnected”. Knowing the “exciting” news, Mr. Hu, manager of the construction department is pleased to announce,”Let make use of this 7 months and grab it! ”—— During the 7 months, the workers first completed the section between the 2 gates and timely restored original water-linking state by mid-April.

Since the plan’s optimization, from building three sheet pile cofferdams to only one cofferdam and use the new construction method of sheet pile cofferdam, anchorage pile and the technological application of ultrasonic determine apparatus, it saves more than 3 months for the whole project. What a good job!

Comparing Nanjing Xuanwu Lake tunnel——the first Chinese city tunnel under the lake, Suzhou Dushu Lake tunnel——the longest lake tunnel and Nanjing Yangtze River tunnel——the largest tunnel in Yangtze, Shuiguohu tunnel also has a number of “the one” features, such as sound insulation screen, hidden pipe lines, bull pier under patent, 12 life-escaping doors, U-turn channel at the mid-way, breathable roof, greenbelt at the top, fire retardant paint and so on. Wuhan Shuiguohu Tunnel is not only the pride of the people in Wuhan, but also the pride of national infrastructure construction!

This article comes from Sheet Pile's Blog edit released