Large Pipe Jacked Half Mile In One Drive

September 2010 Vol. 65 No. 9
The pipes are being supplied by Hobas, and are the largest CCFRPM pipes made to date with an OD of 118 inches.

Europe, like the United States, is struggling to upgrade its infrastructure. In Poland, for example, over 1,000 wastewater treatment plants need to be constructed or upgraded in order to meet European standards which take effect in 2015. Warsaw, the capital and largest city in Poland, has many planned upgrades, including a recent two-year-long project which will provide added capacity and decrease overflows.

One of the driving forces for this new project was environmental, as it is estimated that 30 percent of effluents have been flowing directly into one of the longest and most important rivers in Poland. Warsaw’s proximity to the Vistula River, the environmentally fragile Baltic Sea and the nearby Carpathian Mountains, home to the largest European population of brown bears, made the project a priority. The environmental aspects coupled with the growing population of the area meant the project should proceed quickly.

The Czajka waste water treatment plant is currently being constructed on the river bank of the Vistula River in Warsaw. After its completion, it will treat 80 percent of the Polish capital’s effluents and make sure that no more untreated sewage will harm the flora and fauna along the Vistula.

As part of the development plan, a collector leading to the plant is also under construction. Due to this project’s size, it was divided into three phases. The first phase is a 3.5 mile jacking project along the right side of the Vistula, the second a 4,600-foot jack along the left bank. These pipelines will meet in the third section, the river crossing.

The pipes for all three phases are being supplied by Hobas, and are the largest centrifugally cast fiberglass reinforced polymer mortar (CCFRPM) pipes made to date. Phases one and three utilize 118-inch OD pipes. The river crossing consists of two parallel, 63-inch diameter lines installed within a 15-foot diameter concrete tunnel.

The consortium of contractors, Hydrobudowa 9, PRG Metro and KWG (all belonging to the PBG Group) have now completed the first pipeline section which includes nearly a mile of jacking utilizing two Herrenknecht microtunneling machines. Proximity to the river means the groundwater is high; the typical water table is just below the surface.