Relining of Old Town Sewer with HOBAS Non Circular Pipes in Dresden

The static design is based on the rules and regulations M-127 T2 set by the ATV-DVWK (Abwassertechnische Vereinbarung – Agreement regarding Wastewater – and Deutscher Verband für Wasserwirtschaft und Kulturbau – the German Association for Water Management and Land Improvement). Because the condition of the existing sewer is categorized class III, the calculations by LGA Nürnberg / Ingsoft GmbH were carried out with due consideration of the special geometry and the grouting procedure. Here it proved advantageous that HOBAS NC Line® Profiles are manufactured with definable wall thicknesses, which keeps statically inconvenient imperfections to a minimum. Since the profiles are produced at the factory, there is no subsequent shrinkage that could lead to circular cracks. Because deformations due to inconsistencies in the old sewer are not transferred to the new pipe as would be the case with cured-in-place relining methods these need not be considered.