Sewer Rehabilitation in all Sizes and Shapes for Krakow's old Sewer System

Project ID: [000009]
Country: Poland
City: Krakow
Year: 2008 - 2009
Application:
Wastewater | Special Profiles (NC Line)
Installation: Relining / Sliplining
Total Length [m]: 3800
Nominal Diameter DN [mm]: Non-Circular
Outside Diameter De [mm] -
Nominal Pressure PN [bar]: 1
Nominal Stiffness SN [N/m²]: 630

HOBAS Pipes in All Shapes and Sizes

In 2007, the city council put rehabilitation of 5 km of sewer pipes under 13 roads out to tender. The concrete pipes dated back to 1900-1945 and showed considerable damage: leaks and cracks put the surrounding soil at risk and as most of the pipelines run under heavy traffic routes, the structural load capacity of the sewers also had to be ensured. A consortium PBG - INFRA - PBRSP Kielce won the contract to replace the pipes with a cross section of 800/1200 mm through 3000/2520 mm. Not only could the contractors draw on the very good experience they had already had with HOBAS Products, but also support and technical advice from the HOBAS Experts, particularly regarding the many special sections.

 

Several special profiles were custom made to fit the sewers. The wall thicknesses of these sections were determined to WRc regulations. Installation work then began in May 2008. To rehabilitate the oval sewers, HOBAS NC Sections 1710/1810 mm were produced in three different lengths: 2.35 m long pipes were used in the straight parts and 0.5 - 1 m long ones in the curved parts. The sections were pushed into the old sewer from prepared entry shafts, joined and fixed in place to prevent them from floating or bending while the cement grouting was pumped in. The annulus be-tween the old sewer and HOBAS Profile was carefully filled in stages.


HOBAS NC Line Profile erneuern Abwassersystem in der Innenstadt von Krakau, PL

Zahlreiche Sonderprofile wurden passgenau für die Kanäle gefertigt. Die Wandstärken der Profile wurden dabei gemäß WRc bestimmt. Im Mai 2008 begannen die Verlegearbeiten. Um die oval geformten Kanäle zu sanieren, wurden HOBAS NC Profile 1710/1810 mm in 3 verschiedenen Längen produziert: auf geraden Abschnitten wurden 2,35 m lange Teile verwendet, in Kurven kamen 0,5 – 1 m lange Stücke zum Einsatz. Die Profile wurden an vorbereiteten Startschächten in den Altkanal geschoben, miteinander verbunden und fixiert, um ein Aufschwimmen oder Wölben während der Zementeinspritzung zu verhindern. Der Ringraum zwischen Altkanal und HOBAS Profil wurde in Etappen sorgfältig verfüllt.