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

method of sewer net segmentation and equivalenting

Summary

The design procedure of evaluating a most important index of the municipal sewer net reliability, i.e. relative amount of raw sewage spills resulting from the failure of separate sewer sections is suggested. The design procedure is using a typical characteristic of the system, i.e. its tree-type structure, and lies in the formal substitution of the sewer net for one dummy equivalent pipeline with the reliability parameters that are evaluated with the use of the known rates of failure and rehabilitation of the original (existing) sewer elements. The design procedure is simple and can be used directly by the companies that are operating municipal sewers.

reliability , failure , sewerage network , rehabilitation , state graph , raw sewage discharge amount

Rehabilitation of house drainage systems with the use
of BRAWOLINER^® flexible polymer liners

Summary

Replacement of house drainage systems in apartment buildings with the use traditional technologies encounters active opposition of the residents and is often eliminated. The reason lies in the necessary subsequent renovation of apartments at the owner’s cost. The use of flexible polymer liners provides for rehabilitating house drainage systems with minimum demolition works and high quality within a very short time. This requires beside the availability of process equipment and qualified personnel also shrewd planning and high-quality organizational and preparatory works with account of the specific features of each project. The factors influencing planning and cost of the works are as follows: number of apartments; number of storeys in the building; number of stand-pipes; number of offsets and abuttings; length of the drainage system (stand-pipes, abutting pipes); scope of performing works; labour costs; distance to the object; extra work to provide for the access to the pipeline; scope of plumbing work (if required).

Key words

water disposal system , rehabilitation , house drainage system , rehabilitation , flexible polymer liner