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Assessment of Railway Station Modernisation Combining Risk Analysis with Multi-Criteria Analysis

Author(s): Tomas Javorik,Lukas Tyfa / Language(s): English Issue: 2/2015

When modernising train stations, several options are usually available for the layout of the tracks and its parameters. The best option is chosen by assessing different criteria; it is not an exact procedure, but a compromise between often different perspectives. Many methods are available to aid the decision-making process in these situations; the authors of this article apply mutually combined multi-criteria and qualitative risk analysis to assess two self-proposed options for the modernisation of the Bakov nad Jizerou station (situated in Central Bohemia in the Czech Republic).

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Low Level Clouds Analysis Relating to Synoptic Weather Types at Bratislava Airport

Author(s): Sandra Krollova / Language(s): English Issue: 2/2014

Low level clouds are one of the most important meteorological phenomena, which can significantly influence every flight phase. In general, clouds are visible indicators of physical processes realized in the atmosphere. They provide information about winds, stability, moisture content and travelling weather systems. Knowledge of cloud base is very important, particularly to a pilot on the descent to an airport flying through a cloud. Cloud base is given as the height of the base of the cloud above a particular level (usually ground level). For aerodrome reports and forecasts the base is the height above the official aerodrome level. For international airports, reports should refer to the approach area; for airports equipped with ILS reference should be to the site of the Middle Marker beacon. This paper deals with analysis of diurnal and annual variations of low level clouds at the Slovak international airport in Bratislava. The results are applicable in aviation weather forecasting and characterizing of dynamic climate of the region.

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Development of Test Stand Prototype for Rail Vehicles Brake Components Testing

Author(s): Juraj Gerlici,Tomáš Lack,Jozef Harusinec / Language(s): English Issue: 3A/2014

The paper deals with the new RAILBCOT test stand building reasons explanation. A project features definition is described. There is possible to perform the railway wheel tread profiles wear research under the rail vehicle in operation conditions simulation. This simulation is possible to execute on the test bench. An important feature of the research is the equivalent conicity change analysis. The paper outlines the stand operation principles a main structure components design and components parameters specification, the tests control, data acquisition and data assessment.

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Dynamic Analysis of a Rolling Bearing Cage with Respect to the Elastic Properties of the Cage for the Axial and Radial Load Cases

Author(s): Róbert Kohár,Slavomír Hrček / Language(s): English Issue: 3A/2014

The aim of this paper is to detail the creation of a large tapered roller bearing model with flexible body cages in the Adams program suite for subsequent dynamic analysis and to obtain information about kinematic and dynamic relationships of steel and plastic cages under various operating conditions. The bearing model was made to closely resemble its real-life counterpart, which allows us to estimate load conditions, dynamic conditions of individual bearing parts and interactions between them.

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Design and Stability of Long Span Railway Arch Bridge

Author(s): Jozef Vican,Jozef Gocal,Jaroslav Odrobinak,Richard Hlinka / Language(s): English Issue: 4/2013

The bow-string arch bridge across the Vah River was designed on the main Slovak railway line. Total length of the bridge is almost 451 m, while the lengths of two main spans are 124.8 m. To analyse behaviour of the bridge, spatial transformation model was developed using FEM software. The Eurocodes were applied for all verification procedures. Bridge global analysis and verification of arches against buckling is discussed in more detail. The variation of upper bracing system and its influence on out-of-plane buckling of the arches is presented. Together with an architecture point of view, a minimum load amplifier to reach the elastic instability αcr is used to estimate the suitability of the bracings.

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Buildings Structure Response Due to Railway Traffic

Author(s): Jan Bencat,Krzysztof Stypula / Language(s): English Issue: 2/2013

The free–field dynamic response at the distance and dynamic response of building structures due to railway traffic calculation procedures is described in this paper. The viscoelastic halfspace model is used both for evaluation of the track–soil interaction forces as well as for prediction of the ground–borne vibrations spectral functions at the distance. In the next step these functions are applied for building structure dynamic response calculation via relevant computational building structure model.

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A Multipurpose Robotic Vehicle for the Rescue of Persons and Interventions in Emergency Situations

Author(s): David Řehák,Ales Dudacek,Pavel Poledňák / Language(s): English Issue: 1/2013

At present, multipurpose robotic vehicles represent the best possible solution for the rescue and transport of persons in a state of trauma from places in difficult-to-access terrain, in poor weather conditions and in emergency situations. It is a case of complementary means supplementing the equipment for rescue and emergency response that already exists or is being developed on the basis of a concept drawn in the framework of Integrated Emergency System of the Czech Republic. As a multipurpose means, the vehicle can be used for unmanned remote investigations into situations, for unmanned rescue and materials transport. Simultaneously, a modification to vehicles for places accessible merely by rail is designed.

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Noise Attenuation from Tramway Traffic

Author(s): Miloslav Rezac,Iveta Skotnicova / Language(s): English Issue: 4/2012

The article describes course and results of experiment, which provided influence of change of acoustic absorption properties of concrete tram track surface by using the recycled rubber on traffic noise attenuation. The experiment was carried out in cooperation of the Faculty of Civil Engineering, VSB-TU Ostrava with the companies: the Ostrava Transport Company Plc, ODS - the Transport Constructions Plc, INTERTECH plus, Ltd. and with the Faculty of Mechanical Engineering, VSB-TU Ostrava [2].

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Safety of Railway Systems and Formal/Semiformal Methods

Author(s): Milan Slivka / Language(s): English Issue: 2A/2011

The contribution deals with computer based railway safety systems. It shortly concerns problems associated with using computer systems in comparison with traditional safety systems. The attention is paid to formal and semiformal methods in development and approval of railways systems, seen in the context of standardization and legislation framework. The author summarizes current state of using formal and semiformal methods from whole life cycle point of view of railway safety system in the area of Slovak and Czech railways and possible reasons for their rare use.

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The First Application of The Electrodynamic Wagon Retarder in Poland

Author(s): Jerzy Mikulski,Jakub Mlynczak / Language(s): English Issue: 2A/2011

The article discusses design and installation method of the EDG Electrodynamic Wagon Retarder at the railway siding of the Power Plant Rybnik. It is the first structure of its kind in Poland. Up to now mostly hydraulic brakes have been used in Poland. They were difficult to operate and hardly environmentally friendly due to contamination and noise. Electrodynamic wagon retarders are free from such defects. The issue of introducing new railroad brake construction in Poland is very important because the Polish Railway Lines (PLK) are confronted with the need of devices modernization on a humps. The German railways’ experience confirms the effectiveness of this type of brake. Especially the field tests in Germany and Poland show that the electrodynamic retarders do not have a negative impact on the occupancy control system.

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Construction of High-Speed Tracks

Author(s): Stanislav Hodas / Language(s): English Issue: 4/2011

The current situation and conditions of construction of high speed tracks (HST) in the Slovak Republic and the comparison with the situation abroad. The speed of train sets and the track quality for high speed trains. The dynamics of railway running. The speeds of the HST trains are limited by the respective track state. The tilting train set wagons - increasing the new levels of speeds in railway curves. The time comparison of the high speed trains to air and road transport “from city centre to city centre”. The required conditions and parameters of construction of high speed tracks up to Vmax 200–240 km.h1 within the track modernizations.

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Influence of Parameters of Railway Track Construction on Vertical Dynamic Interaction Vehicle/Track

Author(s): Libor Izvolt,Jan Kardos / Language(s): English Issue: 3/2011

By analysing the dynamic interaction between the railway vehicle and the track we are able to explain complex interactive phenomena that are particularly important in the case of higher and high speed of a moving rail vehicle on railway track.The paper focuses on the solution of the above mentioned problem with the help of numerical computer simulations. The important step on the way to create a respective simulation model is setting objective entry parameters of railway track as well as taking its imperfections into consideration. These imperfections significantly influence the results of dynamic interaction. Out of the considered track imperfections, we particularly solve deformation resistance inhomogeneity of track grid subgrade and vertical irregularities of rail belt.

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Analysis of Selected Pavement Serviceability Parameters

Author(s): Ján Čelko,Matus Kovac,Martin Decky / Language(s): English Issue: 3/2011

The parameters of pavement serviceability have the notable effect to the road life time and to the conditions of safe and comfortable driving. The serviceability of flexible pavements is defined by three parameters: skid resistance, unevenness and pavement distress. The Slovak Road Administration observes 24 specific road sections on which the parameters have been measured two times per year since 1998. The obtained data should be used for determination of the degradation models that describe the qualitative decreasing of the parameters depending on time and traffic load. The functions are very important for definition of the optimal road maintenance and rehabilitation. The degradation models describing the parameters changes over time are the substantial research problem in dependence on many affecting factors. The results of pavement serviceability parameters evaluation are presented in the paper. The basic functions are described and discussed.

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Change of Bearing Capacity Characteristics of Asphalt Pavement

Author(s): Jozef Komacka / Language(s): English Issue: 3/2011

Time succession of data for monitored variable parameter of pavement state is the first step in development of degradation models and determination of degradation functions. Procedure used for characteristics of bearing capacity is described in the paper. Data from long time monitored (since 1995) test section on road network were used. First of all homogeneity of subgrade was tested. The deflections at distance of 1500 mm from load centre were used for this purpose. Data that met criteria of homogeneity were corrected taking into account influence of temperature. Two characteristics of bearing capacity (central deflection and surface curvature index) were evaluated in relation to number of heavy vehicles that had passed test section. Results showed that investigated characteristics of pavement bearing capacity changed in time. It was stated that tendency of development was not very clear because values oscillated in the narrow range. Generally saying the bearing capacity of tested pavement has not changed since 1995 significantly.

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Analysis of Vehicle Bogie Effects on Track Structure - Non-Stationary Analysis of Dynamic Response

Author(s): Milan Moravčík / Language(s): English Issue: 3/2011

The present paper is concentrated on the analysis of in situ vibration measurements during operating conditions in the track structure for loading by current passenger trains at the new built up railway corridor in the section Bratislava – Trnava. Tests were carried out to determine the dynamic track behaviour and relative dynamic effects between the track components – the rails, the sleepers, and the ballast bed during the passage of characteristic passenger trains moving at the operating speeds 70 ÷ 130 km/h. Experimentally obtained signals of the dynamic response of track components – measured as vertical accelerations and displacements of the rails, sleepers, and ballast bed are analysed in detail as the nonstationary random signals corresponding passages of characteristic vehicle bogies (locomotives, coaches). Vertical dynamic response of these components were measured at two different locations of this section and the vertical dynamic behaviour of track components were investigated in the time domain and analysed in the frequency domain up to 500 Hz.

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Dynamic Behaviour of the Arch Bridge - The Full-Scale Testing

Author(s): Milan Moravčík,Martin Moravčík / Language(s): English Issue: 3/2011

In the paper the full-scale dynamic testing procedure for highway bridges is presented. The procedure is applied on the new highway steel arch bridge in highway R1 at the locality Nitra – Selenec. After a general description of the bridge, some results relative to inspection and the spectral analysis are reported. The testing equipment, methods of evaluating and processing obtained records utilised during the forced vibration of the bridge are described.

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New Precast Bridge Girder with Combined Prestressing

Author(s): Martin Moravčík,Petra Bujnakova / Language(s): English Issue: 3/2011

Traditionally, the major part of highway bridges in Slovakia is realized using the precast concrete technology. The common Slovak precast girders are produced to the34 m length as one element. Nowadays, there is an increasing demand for more economical and resisting bridge structures with longer spans. The company Vahostav-Sk-PREFA, Ltd as the main supplier of precast elements for highwaybridge 207, in cooperation with theUniversity of Zilina and the designer company Dopravoprojekt Inc. Liptovsky Mikulas, developed a new precast girder MDP for the span 38 m with combined prestressing. Some experiences and results of verifying flexural test with numerical analysis of that girder are presented in this paper.

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Dynamic Effect of Moving Vehicles on the Road Concrete Slabs

Author(s): Gabriela Lajcakova,Jozef Melcer / Language(s): English Issue: 3/2011

The road concrete slabs represent the typical transport structure exposed to dynamic effects of moving vehicles. Numerical simulation methods demand to pay attention to the proposal of the computing model of the vehicle and the computing model of the road concrete slab. The models must be mathematically described and the equations of motion must be solved in a numerical way. For the solution of such a problem the specialized computer program must be created. It is suitable to use the possibilities of the higher level programming languages as MATLAB. The influence of some important factors on dynamic response of the structure is numerically tested.

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Investigation on Cracks Creation and Propagation in Concrete Slab of Composite Beams

Author(s): Jan Bujnak,Kazimierz Furtak / Language(s): English Issue: 3/2011

Analytical and experimental research have illustrated initiation of cracks in concrete deck immediately after its casting and placing on the upper flange of steel beams, especially prior to application of additional permanent load on composite element. Not only value of concrete shrinkage strain may influence creation and propagation of cracks in concrete. However ratio of deck reinforcement, cross-sectional area of reinforcement steel and strength of concrete can modify the process. Moreover, the ratio of steel beam flexural stiffness and flexural stiffness of concrete deck can be significant. Important shrinkage strains can occur at the lower concrete surface in the steel and concrete interface. Parametrical studies have provided the relationships illustrating impact of above parameters on crack aspect. The aim of the paper is to provide further details.

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Fatigue Resistance of Typical Fatigue Prone Riveted Steel Railway Bridge Structural Detail

Author(s): Jozef Vican,Jozef Gocal,Jozef Jost / Language(s): English Issue: 3/2011

There are still a lot of riveted steel railway bridges built in the first half of 20th century in service, and so it is important to pay attention to their evaluation. Their fatigue resistance represents one of the most determining factors on decision making process oriented to possibility of their further exploitation after finishing their planned service life. The standard method of fatigue assessment according to Eurocode EN 1993-1-9 is based on categorization of structural details, which reflects their predisposition to fatigue failure. The paper deals with laboratory investigation of the riveted connection of stringer to cross beam of a railway bridge deck. This structural detail is typical by frequent occurrence of fatigue cracks, but its categorization according to standard mentioned above is at least questionable. In order to investigate and define the fatigue category of this detail more properly, the laboratory tests on specially adapted specimens were performed.

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