Projects

PL01 Zielona Góra

HOBAS Poland won the award “HOBAS Project of the Year 2001”

At the HOBAS Conference in Prague, which took place in September 2002, the Polish project “Zielona Góra” was awarded “HOBAS Project of the Year 2001”. The first curved pipe jacking project in Poland convinced the members of the jury most. The eight submitted projects were evaluated on a range of criteria covering fields like project scope, technical challenge, competition and popularity.

The project “Zielona Góra” included 1149 meters of HOBAS CC-GRP Sewer Pipe Systems of DE 1099 and 1229 and SN 128000 with a rectilinear and two curved sections with a radius of 350 m and 175 m.


In case of rectilinear microtunneling the compressive force is distributed evenly on the entire pipe. The challenge oft this curved pipe jacking project was the
fact that in the case of angular deflections at pipe connections the compressive force is not applied centrally to the pipe cross-section but acts eccentrically. This fact may result in exceeding the allowable stress, and consequently in pipe damage.

In order to select the right stiffness parameters of the pipes, a number of analyses must be performed beforehand.

According to the analyses, HOBAS CC-GRP Jacking Pipe Systems with a ring stiffness of 128000 N/mm² were selected. The allowable jacking force for such pipes for rectilinear microtunneling was 4660 kN, while for the curved section a jacking force of 3000 kN was allowed. Despite the curve, HOBAS CC-GRP Jacking Pipe Systems with their smooth outside surface could easily be jacked with only 3000 kN. For the curved section 1 m long pipes were selected, while the straight sections were made using 3 m long pipes. The total length of the section was 270 m, of which the final 115.5 m long section was made along a curve with a radius of 350 m. Despite the technical difficulty of curved jacking sections, the daily progress in laying the pipes was up to 8 lengths resulting in a total of 24 m.

Further submissions for the “HOBAS Project of the Year”

• HOBAS Pipe USA: Project Charleston Harbor Tunnel
• HOBAS Pipe Austria: Project Reutte Flood Protection and Relining Project Frastanz
• HOBAS Poland: Sleza Sewer Project, Prymasa Sewer Project
• HOBAS Pipe Germany: Essen Main Sewer Collector
• HOBAS Benelux: HOBAS Pressure Sewer of Big Diameters in the Hague Region

Downloads

project.pdf