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Innovative Spiral-Wound Technology Solution for custom-shaped Storm Water Pipe

SCHIEDER-SCHWALENBERG/GERMANY, August 14, 2013 – The local wastewater authority SIARE (Syndicat lntercommunal d'Assainissement de la Région d'Enghien) had instructed the rehabilitation of its custom-shaped storm water pipe with the Spiral-Wound product SPR after a collapse caused by material fatigue. 110 m of the broken water pipe was rehabilitated within seven weeks. The pipe, based on a box shape with a height of 1150 mm and a width of 2600 mm, is located beneath the road Rue d’Enghien in the French City of Eaubonne, a suburb of Paris.

spiral winding machine in a sewer in Paris

The spiral-winding machine is directly installed in the sewer and is moving through the pipe by winding the PVC profile strip to a pipe. The frame of the machine can be adjusted to the particular custom shape and dimension of the pipe to be rehabilitated. | photo: SEKISUI SPR Europe GmbH

The renewal of this storm water pipe was given high priority from the local wastewater authority SIARE after there had been several collapses on the road d’Enghien before. First, the ground gave way under the high load of a 22-ton roadwork machine. Another one was caused by material fatigue. The two incidents have shown that the rehabilitation of the storm water pipe was required. The pipe covers the Montlignon stream, which has its source in the Montmorency forest and replenishes the lake d'Enghien 10 km southwards. In addition, it also collects the rain water at Rue d’Enghien. The box-shaped sewer lies 15 cm to 1.5 m below the ground level, partly following the traffic route and is located closely to private property.

renovation of an old sewer with the help of the spiral-winding machine

The spiral-winding machine joins by key-and-slot with every rotation the SPR™ profile strip to a new watertight pipe while live flow. | photo: SEKISUI SPR Europe GmbH

Camera inspection to reveal the Damage of the Pipe System

A camera inspection showed the extent of the damage. The pipe had numerous of corrosion damages, cracks and infiltrations. The construction work would be a challenging task: the road section in need of rehabilitation is a one-way street. Therefore possibilities for an alternative routing were limited. Additionally, the storm water pipe often bordered private property, featuring a 10° bend and a dozen of lateral connections.
Different renewal methods were presented to the local wastewater authority SIARE. One of it was the traditional way, which meant digging and rebuilding the storm water pipe. But this would have been the most expensive solution. The other problem was the bad static situation of the pipe. Digging up the pavement could have caused structural damages on surrounding properties. Therefore a trenchless technology was required and SIARE, already familiar with no-dig methods, chose SPR™ as best solution.

sewer after the renovation with the spiral-winding machine

A watertight pipe with high hydraulic performance is the result of the Spiral-Wound pipe rehabilitation method. The high-strength grout between the SPR™ pipe and the old pipe is responsible for the static. | photo: SEKISUI SPR Europe GmbH

Trenchless rehabilitation with SPR

The Spiral-Wound method SPR can not only be used for the rehabilitation of standard-sized circular or box shapes, but also for special profiles of any conceivable type and dimension up to 5000 mm. This trenchless solution convinced SIARE as it meant lower costs and less time consuming rehabilitation. Another advantage of this no-dig solution is that the traffic at Rue d’Enghien was hardly affected. This was important as the road is a one-way road, which goes from the racecourse railway station “Champs de courses” to the city hall in the center of Eaubonne.
The SPRTM Spiral-Wound pipe rehabilitation technology rehabilitated the 110 m decayed storm sewer section by using an endless PVC profile strip, which was continuously wound to a new pipe in the old pipe. The endless profile strip, wound on a spool, was fed into the sewer through a manhole. The spiral-winding machine was installed directly in the sewer. Its frame needed to be adjusted to the box shape. The special feature of SPRTM technology is that the machine crawls along the full length of the structure, combining with every rotation the SPRTM profile strip to a watertight pipe by a key-and-slot joint. Liners of any length can thus be created: as soon as one of the 13 above-ground profile drums was empty, a new one was welded onto it. After the winding process, the annular space between the SPR™ liner and the old pipe was backfilled with a high-strength mortar that ensures the static characteristics of the Spiral-Wound pipe.
The 10° bend as well as several lateral connections were no problem and could be relined in one step. The installation took two and a half weeks from its beginning at late February 2013.

Continuing in the future

For now, the Spiral-Wound technology has been deployed over a 110 m stretch. The goal is to install this method at a total distance of 1.7 km. "We're used to rehabilitate circular-profile pipes, but this custom shape is special and with the inhabited surrounding it poses a special challenge which we can meet with SPRTM“, says Sébastien Yot, SIARE planning department engineer. There will be certainly more rehabilitation projects using the Spiral-Wound product SPRTM in France.
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