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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.

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.

This article concerns the assessment of selected physical and mechanical properties of a dump soil. The dump soil is a specific soil with a very heterogeneous internal structure. Next to each other, there may be lumps and crumbs of cohesive soils mixed with non-cohesive soils accompanied by a very diverse admixture of organic substance. In addition, the soil in the waste dump, in spatial terms, may significantly differ in consistency and density. This is the result of the process of forming a dump soil, which takes place in three stages: excavation, transport and dumping. A heterogeneous soil deposited within the waste dump is subject to further processes: consolidation, compaction and creeping. Changes occurring in the course of these processes have a significant impact on the development of the properties of the dump soil. Due to the large diversity of the tested soils, the results of their properties were divided into two groups, based on type and consistency of soil. This allows us to estimate the selected properties of the dump soil only on the basis of their macroscopic analysis.

This paper discusses the pull-out laboratory tests and the monitoring of expansion-shell bolts with a length of 1.82 m. The bolts comprised the KE-3W expansion shell, a rod with a diameter of 0.0183 m and a profiled, circular plate with a diameter of 0.14 m, and a gauge of 0.006 m. The bolts were installed in a concrete block with a compressive strength of 75 MPa. The tests were conducted on a state-of-the-art test stand owned by the Department of Underground Mining of the AGH University of Science and Technology. The test stand can be used to test roof bolts on a geometric scale of 1:1 under static and rapidly varying loads. Also, the stand is suitable for testing rods measuring 5.5 m in length. The stand has a special feature of providing the ongoing monitoring of bolt load, displacement and deformation. The primary aim of the study was to compare the results recorded by two different measurement systems with the innovative Self-Excited Acoustic System (SAS) for measuring stress variations in roof bolts. In order to use the SAS, a special handle equipped with an accelerometer and exciter mounted to the nut or the upset end of the rod was designed at the Faculties of Mining and Geoengineering and Mechanical Engineering and Robotics of the AGH University of Science and Technology. The SAS can be used for nondestructive evaluation of performance of bolts around mining workings and in tunnels. Through laboratory calibration tests, roof bolt loads can be assessed using the in-situ non-destructive method.