UDC 628.2:621.644.073
DOI 10.35776/VST.2024.10.07
Zakharov Iu. S.
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
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UDC 628.3:62-192
Alekseev M. I., Yermolin Yu. A.
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
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UDC 628.2:621.644.073
DOI 10.35776/VST.2024.12.08
Zakharov Iu. S.
Determining the wall thickness of flexible polymer liners for the rehabilitation of pipelines of the state class I
Summary
The wall thickness is one of the main parameters that determine both the service life of a gravity sewer pipeline subject to rehabilitation with the use of flexible polymer liners, and the economic efficiency of repair and rehabilitation activities. The wall thickness of a flexible polymer liner is determined based on a static calculation with the algorithm depending on the condition of the pipeline subject to rehabilitation and the loads acting on it. At present, special software developed by foreign companies is used to calculate the wall thickness of a flexible polymer liner. A method for static calculation of flexible polymer liners cured inside a pipeline is proposed that while using tables and graphs allows determining the liner wall thickness during the rehabilitation of a state class I pipeline, provided the main load acting on the «new polymer pipe – pipeline» system is groundwater pressure.
Key words
pipeline , water disposal system , rehabilitation , flexible polymer liner , static calculation
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UDC 628.2:621.644.073
DOI 10.35776/VST.2024.12.09
Zakharov Iu. S.
Determining the wall thickness of flexible polymer liners for the rehabilitation of pipelines of the state class II
Summary
Once gravity sewer pipelines are put into operation, longitudinal cracks may appear in the pipes after a relatively short period of time caused by the low quality of pipe products and violation of the construction technology. Pipelines with longitudinal cracks (state class II or III) can be rehabilitated using flexible polymer liner, provided that the «pipeline – soil» system is statically stable. A method for estimating the static stability of the «pipeline – soil» system is given. Taking into account the properties of the soil, backfilling and ovalization of the pipeline, the main loads acting on a new polymer pipe during the rehabilitation of pipelines with longitudinal cracks (condition class II) are determined. An algorithm is proposed for calculating the wall thickness of a flexible polymer liner for the rehabilitation of pipelines of the above-mentioned state class depending on the actual loads. As an alternative to using foreign specialized software, a method is proposed for calculating the wall thickness of a flexible polymer liner that provides for using tables and graphs to determine the wall thickness of the liner for the rehabilitation of state class II pipeline on exposure to the soil pressure, groundwater and transport loads.
Key words
pipeline , water disposal system , rehabilitation , flexible polymer liner , static calculation
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UDC 696.1
Stepanov Mikhail, Zakharov Iu. S.
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
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