1.7 Kilometre pipe liner installed in Speyer
Corrosion, structural damages and extreme fat deposits in places necessitated the rehabilitation of sewage piping with a total length of 1.7 kilometres in the city of Speyer in Rhineland-Palatinate. The project was given to the company ehnes GmbH from Germersheim; light-curing pipe liners from Brandenburger were employed. The rehabilitation project was carried out in March and April 2011.
Drawing in the liner
The project, for which the sewer rehabilitation specialist ehnes GmbH, based in Germersheim, received the contract from the municipal waste disposal company of Speyer, included the complete repair of a total of 1700 metres damaged concrete sewers. The sewage pipes from the 60s lie in a residential area near the centre of town. Speyer's St. Vincentius hospital is also located nearby. The sewers with circular profiles of DN 300 to 800 as well as oval profiles of 400/600 to 700/1050 showed serious corrosion and structural damage, plus extreme fat deposits in places. The municipal waste disposal company of Speyer therefore decided in 2010 to call for tenders for the comprehensive installation of pipe liners to prevent possible collapsing and to achieve a long-term preservation.Working at night ensures vehicle access to the hospital
During the 40-day duration of the project, segments were rehabilitated at lengths of 20 metres to 160 metres. A strict schedule was mandated by the city to limit the traffic problems and inconveniences for local residents as well as the hospital operations as much as possible. Since vehicle access to the hospital needed to be ensured and also due to the great amounts of wastewater in the larger sewers, the ehnes team did part of the work at night. In addition, extensive water drainages needed to be installed due to the, in parts, extra large sewers.The affected sewage sections were calibrated first of all and the pipes thoroughly cleaned. Due to the prevalent fat residues in the sewer this was not an easy task in some places, reports Hans Kreuzer, project manager and director at ehnes. Obstacles such as protruding ports or intrusions were removed by own milling robot equipment of the rehabilitation company.
After all sewer stretches to be rehabilitated were thus prepared, the actual pipe lining with light-curing Brandenburger liner commenced by sections. On average, the ehnes team installed 150 metres per day, which approximated the processing of one section per workday. Directly after the liner installation, the necessary partial projects followed: Using robots, the previously dimensioned side inlets were milled open, their ports then reconnected on the next day - also with robot equipment - before finally the shaft rehabilitation including the connection of the liner ends was executed. 160 metres DN 300 were cured in 3.5 hours
Using the rehabilitation process of the section in the Hafenstraße of Speyer, which was the longest one with 160 metres, as an example, the rapid execution with Brandenburger liner can be presented. After the DN 300 pipe under the quiet residential street was rinsed, the first work step was to insert the protective foil for the liner. Afterwards, the Brandenburger GFRP liner, which was impregnated in the factory with light-curing polyester resin and delivered ready for installation, was drawn in by a cable winch, sealed with packers and pressed against the old pipe walls by pressurised air. A camera inspection showed the flush and non-wrinkling position of the 4.2-millimetre thick liner. For the curing at a pressure of 500 mbar, a light chain with 8 lamps, each with 400 watt, was drawn in. The curing at a curing speed of 0.9 m/min was completed after 3.5 hours.
Work at night was necessary in some instances
Efficient processes reduce administrative expenses
Just like this 160 metre long segment, the other sections could be rehabilitated as scheduled. The quick curing times contributed to the quick and smooth proceedings in the tight time frames in addition to the good preparation and routine working methods of the construction site team. "The ehnes Company provided very good work," stated Mr Riedel, the engineer who was appointed by the waste disposal company with planning the rehabilitation. This was also proven in the only one-metre wide Bauergässchen, where the liner installation was carried out without a problem. "For such cases, it is important that the transport crates of the liner are already dimensioned according to the liner," emphasised ehnes' project manager Kreuzer. For Riedel, the advantages of the liner procedure with UV light curing comes to bear in several aspects. "In addition to the quick curing, the setting up and dismantling of the construction site is carried out quicker and above all, contrary to the usage of needled felt, all ports can be opened up right after the curing." That is an advantage for the construction supervision, because the construction site does not need to be visited a second time, which reduces the documentation and administrative expenses. "And of course, the client prefers to have a quickly completed construction site." ehnes GmbH offers all services in sewer rehabilitation from a single source
Roland Herr, owner and director of ehnes GmbH, emphasises just as engineer Riedel and project manager Kreuzer the good cooperation with the Speyer municipal facilities, in particular with the engineer responsible for planning and executing rehabilitation projects, Stephan Wittner. Thus, the construction site consultation and the taking of sample pieces are done in the course of a regular weekly meeting. This ensured a continuous exchange of information between all participants.
In addition to the good cooperation with the client, ehnes' director Mr Herr considers the professional qualification of the employed personnel a central factor for the cost effectiveness and quality of pipe lining projects. Since 2009, ehnes GmbH relies on the Brandenburger procedure with thoroughly good rehabilitation results. "In 2010, we sent in about 70 samples of cured pipe liner for inspection and there was not a single complaint." Based on this, his company can also offer clients a high guarantee for their investment, says the sewer rehabilitation specialist, who operates with trenchless procedures since 1980. Decisive for the decision for the Brandenburger system was, besides the quality, also the regional proximity of the rehabilitation specialist to the company in Landau. This allows us to pick up the liners ourselves from nearby and to call on quick support by the manufacturer if needed.
In addition to liner installation, sewer inspection and cleaning, trenchless partial repairs with powerful robot systems are a main focus of ehnes GmbH. Thus, the company has developed a new procedure for branch pipe rehabilitation by which up to 15-metre long side sewers can be processed from the main sewer.
Contact and additional information
Brandenburger Liner GmbH & Co. KG
Taubensuhlstr. 6
76829 Landau (Palatinate), Germany
Tel.: +49 6341 5104-0
info@brandenburger.de
www.brandenburger.de
Hertha Ehnes Kanalreinigung, Kanalsanierung GmbH
Freiherr-v.-Stein-Str. 2a
76726 Germersheim
Tel. 07274 / 50 08 0-0
Fax 07274 / 50 08 0-29
ehnes-gmbh@t-online.de
www.ehnes-gmbh.de
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