Multiscale Modelling in Railway Engineering

The article presents the design and operation of selected types of physical simulation models of the railway track subgrade and transport earthen structures. These models include:- model section of railway track for testing vertical displacements,- test bench physical simulation models of reinforced railway track subgrade,- multiscale physical simulation model of the retaining wall made of reinforced ground stabilizing the transport embankment,The paper discusses the research of the displacement state of the models constructed. The results of research can be the foundation for designing subgrade reinforcements in modernised railway tracks

Effectiveness of road embankment reinforcement in the light of model tests on a laboratory scale

The subject of the article concerns road embankments made of reinforced soil. The results of the analysis of the effectiveness of the reinforcement of these structures as a function of selected variable factors concerning the soil medium and the parameters of reinforcement inserts are given. The efficiency analysis was carried out on the basis of measurements of the horizontal unit pressure made on a physical model of a soil massif with a vertical wall of reinforced soil. The large-scale model was constructed on a laboratory scale. The article ends with a summary containing conclusions of a cognitive and practical nature

Electrofusion tensometry applied to the research of engineering structures

The subject of the article concerns the problem of estimating the location of a slip line in a massif with a vertical retaining wall made of reinforced soil, in which the limit state of active pressure was induced. The task is solved experimentally, on the basis of measured unit strains in the reinforcement inserts, with the use of electrofusion strain gauges. The inserts are located in horizontal layers. The slip curve is formed by the points where the maximum normal stresses occur in the reinforcement inserts. This curve cuts off the fragment wedge that is being sought from the plane of the retaining wall. The slip line divides the area of the massif into two zones: active (splinter wedge) and passive, in which the reinforcement inserts are anchored.The test stand is presented, the technique of measuring the deformation of the reinforcement and the method of estimating the location of the slip surface are discussed

Investigation into the Efficiency of Strengthening of Subgrade at the Proof Ground of Road Surface

The aim of the investigation is the analysis of strengthening systems of road surfaces situated at the weak subgrade. The paper presents three systems of strengthening of road surface using geotextiles. The results of the analysis of road surface deformation moduli values are discussed. The value of deformation modulus on the basis of measurements of vertical displacements of loaded road surface was calculated. The investigations at the proof ground of road surface was executed. Particular efficiency of the use of GEOWEB cellular mattress as strengthening of road surface was confirmed

Lateral Earth Pressure in Non-Cohesive Soils, Reinforced with Geotextiles in the Light of Laboratory Research

The subject of the paper is the non-cohesive medium layer with geotextiles reinforced as foundation in communication building engineering. The influence of horizontal bidirectional reinforcement on the change of value of horizontal pressure in the laboratory physical models of ground medium layer is estimated. The most important effects reinforcement have been observed, regarding increasing model load capacity

Ways of eliminating the road effect in transition zones from the railway track to bridge structures

 Selected methods of constructing special inserts in the transition zones between the embankment of the railway track and the engineering object (bridge, viaduct, or culvert) were discussed. The purpose of mounting the designed inserts is to eliminate the so-called threshold effect, i.e. continuously creating a mild change in the stiffness of the ground under the track. In addition to the solutions presented in practice, attention was also paid to projects developed by the authors of this article. The results of experimental research constituting the basis for the development of some solutions are also given

Model Studies of Distortion Condition Resistance Wall from Gabionic Elements

Retaining walls have been classified and characterized as structures protecting road or railway embankments against landslides. Particular attention was focused on retaining structures classified as light [1-3, 5-12, 14-24], which include, among others, walls made of gabions. Physical models of the gabion retaining wall, prepared on a laboratory scale, test stand and how to perform spatial deformation tests are presented. The models differed in the number and dimensions of gabions. On the basis of measured horizontal deformations of embankment models with a gabion wall, which were subjected to vertical static pressure at the level of the embankment ceiling, the values of basic strength parameters were determined. In particular, the value calculated: horizontal pressure coefficient, shear strength and modulus of deformation. The variability of the values of these parameters was estimated as a function of variable factors related to the gabion wall configuration (determined by the number and dimensions of gabions) and the value of the external load test

Logistics Problems of Designing a Route for Public Rail Transport in the Psie Pole District in Wroclaw

The text discusses current problems of the public rail transport in the Wroclaw agglomeration, as well as the opportunities for its extension and future plans of the Wroclaw Municipality in that respec