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Trenchless pipe installation

News International-French

16 Apr 2011

An impressive project in Poland’s capital, Warsaw, involves microtunneling to install 3.3 km of pipe. The project is expected to be completed by mid-summer 2008.

(Published on July-August 2008 – JEC Magazine #42)


To relieve the downtown sewer collector and to transport wastewater to the new “Czajka” treatment plant, 3.3 km of Hobas CCGRP large-diameter jacking pipes (up to 2,160 mm) are being installed by remote-controlled jacking, or microtunneling. The pipes have literally been driven around several bends!


Trenchless technologies are the most convenient and reasonable way to install a pipeline in a city. Project requirements such as installation depths up to 10.6 m convinced the municipality, waterworks and designer to opt for this solution. Furthermore, the installation method per se saved on pumping costs, as the line was partly established up to 2 m below groundwater level.


The competition was tight, and material prices certainly did not favour GRP. As is often the case, however, a closer look showed that other savings would outweigh the higher material costs. For instance, the smaller, consistent outer diameters of the comparably thin-walled CC-GRP pipes led to a 30% reduction in the amount of soil to be extracted. Further costsaving advantages that spoke for Hobas were fast assembly, small curve radii, and the products’ high corrosion resistance, long service life, and low maintenance costs.