Implementation and evaluation of the effectiveness of geotextiles in the construction of railway track subgrade in areas with increased dynamic loads.
Students Name: Hazdun Marian
Qualification Level: magister
Speciality: Functional Safety of Railway Transport
Institute: Institute of Mechanical Engineering and Transport
Mode of Study: full
Academic Year: 2025-2026 н.р.
Language of Defence: ukrainian
Abstract: The durable and reliable performance of a railway track depends on the condition of both the superstructure and the substructure. One of the modern engineering solutions in railway design and construction is the use of geotextile materials [1–4]. Studies on the application of geotextiles in track structures show a positive effect, which consists in providing a drainage function [4–7]. Geotextiles also play a reinforcing and separating role in the track [8]. The main advantage achieved when geotextiles are used in the track structure is the reduction of railway ballast fouling. In many cases, there is also a decrease in subgrade deformations and an improvement in drainage properties [1]. This contributes to increased track stability and reduced maintenance costs. However, there are cases of track operation with geotextiles where they do not perform their functions [9–13]. This is related both to the quality of the material and to the correctness of its installation during track maintenance. In such cases, defect accumulation occurs on the railway track. Therefore, an important task of this master’s thesis is to study and evaluate the effectiveness of geotextile application in the railway subgrade structure under conditions of increased dynamic loads. Object of research – the structure of the railway subgrade reinforced with geotextiles. Subject of research – the stress-strain state of the railway subgrade structure with geotextiles. Purpose of research – to evaluate the effectiveness of geotextile application in the railway subgrade structure under conditions of increased dynamic loads. According to the results of the master’s thesis, the following research tasks were completed: -an analysis of the advantages and disadvantages of using geotextiles in railway track structures was carried out; -a review of research works on track operational stability when using geotextiles was conducted; -numerical modeling of the stress-strain state of the railway subgrade with geotextiles under increased dynamic loads was performed; -recommendations were provided regarding the effective installation of geotextiles in the track structure. The analysis of scientific works [2–5] on the given research problem has shown that in most cases geotextiles perform a drainage function. At the same time, the effectiveness of geotextile application is more evident on sections of track with weak soils. It has been established that, according to the requirements of the European standard EN 13250 [14], geotextiles or geotextile-related products must perform one or several of the following functions in the railway track structure: filtration, separation, and reinforcement. The results of numerical calculations and studies of the stress–strain state of the railway subgrade reinforced with geotextiles showed that the maximum vertical stresses in the subgrade amounted to 56.88 kPa, while in the geotextile they were 17.7 kPa. At the same time, the maximum vertical deformation of the subgrade was 3.24 mm, whereas the vertical deformation of the geotextile was 1.29 mm. It was determined that the maximum horizontal stresses in the subgrade body under the action of an axial load of 20 t from the CS7 rolling stock amounted to 22.45 kPa, while in the geotextile they reached 4.01 kPa. At the same time, the horizontal deformation of the subgrade was 1.18 mm. The conducted numerical studies established that the geotextile performs a reinforcing function in the railway subgrade structure, which is explained by the presence of a stress–strain state in the geotextile under the action of railway rolling stock. The analysis of research works, in particular [1], showed that the use of geotextiles leads to a reduction in the number of defects on track sections compared to those without geotextile materials. Key words: railway track, subgrade, geotextile, stresses, deformations.