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Laboratory tests and analysis of CIPP epoxy-resin internal liners used in pipelines – part I: comparison of tests and engineering calculations

Abel Tomasz

Studia Geotechnica et Mechanica

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2021

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Vol. 43, nr 2

169--180

EN

Tests that were carried out in order to obtain knowledge of the actual values of strength parameters obtained by CIPP liners that are used to repair pipelines. Specimens of liners made of high quality polyester felt cured with epoxy resin were subjected to tests. The scope of the performed studies corresponded with the scope of acceptance tests, which are carried out in the investment process during quality control of renovation works. Specimens of liners taken from sewers with 3 different diameters, i.e. 200mm, 350mm and 500mm were selected as representative for underground sewage networks. The obtained results enabled the calculations carried out in the course of design work to be verified, and differences between the model values of the strength parameters obtained from the calculations, and real values that are burdened with irregularities resulting from the conditions prevailing at a construction site and which were obtained for specimens taken from their built-in locations to be compared. The tests confirmed that it is possible to renovate - using CIPP liners - sewers with a lot of structural and material damage that negatively affects a liner‘s geometry. The implementation of the reinforcing internal coating in a sewer enables its further safe operation. The direct application value of the research involves the enlargement and clarification of knowledge concerning the actual load-bearing capacity of CIPP liners.

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Laboratory tests and analysis of CIPP epoxy resin internal liners used in pipelines – part II: comparative analysis with the use of the FEM and engineering algorithms

Abel Tomasz

Studia Geotechnica et Mechanica

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2021

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Vol. 43, nr 3

307--322

EN

In the case of underground network infrastructure it can be seen that objects functioning in the second technical condition, according to DWA-ATV 143-2, and subjected to rehabilitation with the use of close-fit trenchless technologies are capable of withstanding external loads. The main external load that is taken into account in engineering calculations in the case of conduits in the second technical condition is external groundwater pressure. In order to compare design parameters obtained with the use of various calculation methods, a comparative analysis was conducted in order to determine the values of critical pressure. The calculations were carried out using popular engineering algorithms. In addition, analyses using the Finite Element Method and Abaqus software as a computational tool were carried out for the purpose of verifying laboratory tests. This paper aims to broaden knowledge concerning the possibility of performing control numerical analyses for close-fit liners installed in pipelines that are in the second technical condition according to DWA-ATV 143-2. The analyses were carried out on ten 3D models. The models were parameterized in order to reflect the CIPP samples in the most accurate way. The computational models were built based on assumptions, which are commonly used in this type of scientific analysis, regarding material parameters and their interactions. The direct value of the performed engineering calculations and numerical analyses is the extension of knowledge in the field of strength parameters that are obtained by various material groups of close-fit liners. Comparative analysis of the results of laboratory tests and numerical analyses, and the conclusions that result from them, constitute the basis for the optimization of the design process and the individual approach to issues related to the use of liners that strengthen underground pipelines.

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Changes in strength parameters of pipelines rehabilitated with close-fit Trolining liners – numerical analysis based on laboratory tests

Abel T.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 1

30--40

EN

Underground network infrastructure shows that even objects functioning in the third technical condition, according to ATV A127, and subjected to rehabilitation with the use of close-fit trenchless technologies are capable of withstanding external loads. It is necessary to conduct analysis and research regarding the mechanical properties of pipelines strengthened with close-fit liners. Calculations, based on laboratory tests, were carried out using the Finite Element Method and Abaqus software as a computational tool. This paper aims to increase knowledge in the area of the possibility of using close-fit liners for pipelines operating in the second technical condition according to ATV A127. A direct and applicable value of the carried out calculations is to provide knowledge about the real bearing capacity of conduits renewed with close-fit liners, and in particular a Trolining liner. The knowledge gained as a result of research, which was conducted in the previous stage, and calculations can be a basis to undertake a discussion on the selection of the strength parameters of close-fit liners.

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Laboratory tests of pipelines reinforced with close-fit Trolining liner

Abel T.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

427--435

EN

Examinations outlined above were run to get knowledge about real load bearing capacity of conduits rehabilitated with close-fit liners. The versatility of testing stand constructed allows to model various soil media and to simulate various kinds of loads. This testing stand provides better chances for more comprehensive diagnosis of underground conduit operating conditions not limiting it to its reinforcement problems. Conduits made of various materials could be tested, so new perspectives for research work at Civil Engineering Institute are new broken open. A series of testing carried out to verify the bearing capacity of Trolining liner has enabled determination of bearing capacity of conduit rehabilitated with this sleeve-type technology. Furthermore, it was proved that renovation with Trolining type liners is possible for conduits in very poor technical condition (deflection of about 10%), in order to prolong their operation. A value of direct applicability resulting from these tests is the knowledge of real load bearing capacity of conduits rehabilitated with close-fit liners, and especially the Trolining one.