TPi October 2009

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60 Tube Products International October 2009
Long-section repairs using
Simona PE 100 pipes and the
Close-Fit method
By Philipp Singer, Ludwig Pfeiffer Hoch- und Tiefbau, Germany, and Jürgen Allmann, Simona AG, Germany
The planning specialists of the BWB always consider
pending construction projects integrally. The following
question is always the focus of the decision-making
process: how can the required construction activity be
implemented economically, with as little impairment
to traffic, nearby residents and the environment as
possible in the shortest possible time?
Preference is increasingly given to state-of-the-art repair
methods. This was the case with a construction project
implemented by German construction company Ludwig
Pfeiffer in the summer of 2008. An approximately 100
year-old grey cast iron DN 1,050 pipe was repaired
to prepare for a road-construction project in Berlin-
Neukölln, in the District of Rudow.
The road, located in the centre of the district, is the main
shopping street in the area, so operating restrictions on
the shops had to be minimised. Consequently, the road
was to be fully cordoned off on only one weekend, from
Saturday at 8 am to Sunday at midnight.
Only two construction pits, one at the start and one
at the end, were planned for the construction section,
with a length of over 500m. This required a 504m-long
repair section. The pipe also ran in a section with an
approximately 10° angle – a special challenge for the
pipe material (Figure 1 ).
The planners at the BWB drew up the following
requirement profile for selecting the method:
Inliner of new-pipe quality
•
Maintenance of the flow capacity •
The new inliner should absorb all load influences •
Pipe material with excellent hydraulics and a •
particularly long service life
Only slight impairment to traffic flow •
Short construction time •
Long repair sections •
Draw-in possible even at points where angles occur •
in the pipe axis
High economy (less costly than open design) •
T he following article examines new developments
in the field of repair of large-diameter pipes.
Advances in technology, machinery and the availability
of large-diameter polyethylene pipes are increasingly
making it possible to treat larger lengths of pipework
– a development which, with improved cost-efficiency,
is pushing back the limitations to use of the Close-Fit
rehabilitation method.
Selection of the rehabilitation method
Greater Berlin is subdivided into several drainage
zones. Sewers which transport water under gravity
route the waste water to a total of 147 pumping plants.
From there, the waste water is transported through
a 1,127km-long discharge pipe network to the six
sewage-treatment plants. Since the year 2000, Berlin
Water Resources Authority (Berliner Wasserbetriebe
BWB) has also been using Close-Fit methods with
pipes made of polyethylene (PE) for repair of the piping
system.
Close-Fit processes hardly reduce the hydraulic cross-
section of the pipes. Particularly in the case of waste
water discharge pipes, reductions in hydraulic capacity
are frequently not possible owing to the rating for
heavy-rain events.
Figure 1 ▲
▲ : The high flexibility of Simona PE 100 pipe permits
extremely tight radii