Classification of gravity sewers at the pipeline rehabilitation
with flexible polymer liner

Summary

One of the dynamically developing areas of the construction industry since the early nineties of the last century has been the rehabilitation of damaged underground pipelines using «pipe-in-pipe» technologies. The rehabilitated pipeline shall meet the requirements for new pipelines, i. e. be hermetic, environmentally safe and safe in service, resistant to static loads, to transported wastewater, to abrasion and loads during water blasting. Based on the static calculation performed when selecting the parameters of a new pipe for pipeline rehabilitation, it is necessary to confirm the bearing capacity, serviceability and steadystate stability of the pipeline after rehabilitation, as well as, if necessary, the impossibility of soil collapse (sinking). A clear definition of the required wall thickness of a new polymer pipe, the choice of a suitable technology for pipeline rehabilitation and the service life of the pipeline after rehabilitation largely depend on the correct classification of the pipeline being restored. Therefore, in order to perform a high-quality static calculation, minimize errors in selecting the design and parameters of a flexible polymer liner, as also to ensure long-term trouble-free operation of the «new pipe – pipeline – soil» system, a visual inspection of the pipeline being restored should be carefully carried out in accordance with the classification given in the article.

Key words

pipeline , water disposal system , rehabilitation , flexible polymer liner , statistic calculations