June 2015, Vol. 70, No.6
New Products
Herrenknecht’s Pipe Express Performs Fast Install Through Groundwater
Herrenknecht’s newly developed semi-trenchless method for pipeline installation has completed its third successful undertaking.
South of Stockholm, Sweden, using Pipe Express, Züblin Scandinavia AB installed a water pipeline more than one kilometer (3,281 feet) in length within 12 days. Groundwater lowering was not required despite a water level just below the terrain’s surface. Compared to conventional open-cut construction, the method has significantly less impact on the environment, while simultaneously minimizing costs.
The benefits were obvious to Mats Ohlsson, project manager of client Stockholm Vatten: “For open-cut construction we would have needed sheet piles and we would have had to lower the groundwater.”
The Pipe Express method from Herrenknecht, however, requires no lowering of the groundwater. The construction company made the most of this enormous budget and time advantage. It used Pipe Express for the laying of a 1,036 meter (3,398 feet) long section of a 48-inch water pipeline near Huddinge. Drilling began on Feb. 22, and by March 5, the destination already had been reached. In the most productive 12-hour shift, 221 meters (725 feet) of pipeline disappeared into the ground; the average construction performance was 0.70 meters (2 feet, 4 inches) per minute. About 60 percent of the construction time was taken up just with welding and coating the 224 meter (734 feet) long steel pipe strings.
Michael Lubberger, senior product manager-pipeline at Herrenknecht, said, “After the pilot project in the Netherlands and the subsequent deployment in Thailand, this is already our third drive with Pipe Express. We see strong potential for the new method on the pipeline market.”
Pipe Express method uses a buggy with a trenching unit to create a narrow 40 centimeter (15.75 inch) wide trench on the surface. Below the soil, a boring machine is mounted that digs the actual tunnel with diameters of up to 1.50 meters (4 feet, 11 inches) and lays the pipeline at the same time. The excavated soil is brought to the surface by the trenching unit and backfilled in the trench again behind the machine. The pushing force for both the excavation unit and pipeline is provided by a Herrenknecht Pipe Thruster located at the starting position.
In contrast to the conventional construction method, the corridors including construction paths are up to 70 percent narrower. Extensive earthworks, groundwater lowering, the ramming of sheet piles, etc. are not necessary. Up to 2,000-meter (6,561 feet) long pipelines with a diameter of 900-1,500 millimeters (36-60 inches) can be laid quickly and cost-efficiently. +49 7824 302-5400, http://www.herrenknecht.com
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