Communications - Scientific Letters of the University of Zilina, 2011 (vol. 13), issue 3
Articles
Fatigue Resistance of Typical Fatigue Prone Riveted Steel Railway Bridge Structural Detail
Josef Vican, Jozef Gocal, Jozef Jost
Communications - Scientific Letters of the University of Zilina 2011, 13(3):5-8 | DOI: 10.26552/com.C.2011.3.5-8 
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...
Investigation on Cracks Creation and Propagation in Concrete Slab of Composite Beams
Jan Bujnak, Kazimierz Furtak
Communications - Scientific Letters of the University of Zilina 2011, 13(3):9-13 | DOI: 10.26552/com.C.2011.3.9-13
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...
Dynamic Effect of Moving Vehicles on the Road Concrete Slabs
Gabriela Lajcakova, Jozef Melcer
Communications - Scientific Letters of the University of Zilina 2011, 13(3):14-18 | DOI: 10.26552/com.C.2011.3.14-18
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.
New Precast Bridge Girder with Combined Prestressing
Martin Moravcik, Petra Bujnakova
Communications - Scientific Letters of the University of Zilina 2011, 13(3):19-23 | DOI: 10.26552/com.C.2011.3.19-23
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...
Dynamic Behaviour of the Arch Bridge - The Full-Scale Testing
Milan Moravcik, Martin Moravcik
Communications - Scientific Letters of the University of Zilina 2011, 13(3):24-32 | DOI: 10.26552/com.C.2011.3.24-32
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.
Analysis of Vehicle Bogie Effects on Track Structure - Non-Stationary Analysis of Dynamic Response
Milan Moravcik
Communications - Scientific Letters of the University of Zilina 2011, 13(3):33-40 | DOI: 10.26552/com.C.2011.3.33-40
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,...
Polychlorinated Dibenzodioxins and Dibenzofurans Emissions from Transportation
Jiri Huzlik, Roman Licbinsky, Daniela Durcanska
Communications - Scientific Letters of the University of Zilina 2011, 13(3):41-47 | DOI: 10.26552/com.C.2011.3.41-47
Measurement of Persistent Organic Pollutants (POPs) was performed in order to complement the set of known emission factors. Methodology for gasoline engines emission factors determination that uses POPs concentrations measured in exhaust gasses, limited pollutants emission factors (carbon monoxide CO, nitrogen oxides NOx and hydrocarbons HC) and other compounds (carbon dioxide CO2) was elaborated. Empirical value of exhaust gasses production announced by specialists of TUV SUD was used for diesel. Emission factors of four vehicle-fuel systems were determined particularly 11 congeners of Polychlorinated Dibenzodioxins (PCDDs), 34 congeners of Polychlorinated...
Significance Evaluation of Environmental Aspects
Marcela Malindzakova
Communications - Scientific Letters of the University of Zilina 2011, 13(3):48-51 | DOI: 10.26552/com.C.2011.3.48-51
The identification of environmental aspects is an essential premise for implementation of EMS in a production company, but not a sufficient one. In order to effectively reduce negative environmental impacts, first it is necessary to undertake a thorough examination of given environmental aspects. For this purpose, several methods can be used. In this article, 3 such methods are described in detail, namely the method of Total pair comparison, the Rank method and the Saaty method. A properly prepared classification of all involved environmental aspects, evaluated by their importance can be considered a first step for successful environmental pollution...
Change of Bearing Capacity Characteristics of Asphalt Pavement
Jozef Komacka
Communications - Scientific Letters of the University of Zilina 2011, 13(3):52-55 | DOI: 10.26552/com.C.2011.3.52-55
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)...
Analysis of Selected Pavement Serviceability Parameters
Jan Celko, Matus Kovac, Martin Decky
Communications - Scientific Letters of the University of Zilina 2011, 13(3):56-62 | DOI: 10.26552/com.C.2011.3.56-62
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...
Influence of Parameters of Railway Track Construction on Vertical Dynamic Interaction Vehicle/Track
Libor Izvolt, Jan Kardos
Communications - Scientific Letters of the University of Zilina 2011, 13(3):63-70 | DOI: 10.26552/com.C.2011.3.63-70
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,...
Analysis of Practical Stability for Time Delay and Distributed Parameter Systems
Djordje N. Dihovicni
Communications - Scientific Letters of the University of Zilina 2011, 13(3):71-76 | DOI: 10.26552/com.C.2011.3.71-76
This paper points to sufficient conditions for practical stability of linear systems with time delay in state. Particularly, in control system engineering practice, despite the contribution to the contemporary control theory and system thinking, the problems of practical stability are not developed in details. Taking into account that the system can be stable in a classic way, but it can also possess inappropriate quality of dynamic behavior, and because of that, it is not applicable. For engineers it is crucial to take the system into consideration in relation to permitted states in phase space which are defined for such a problem, Dihovicni et al....
Video-Analysis of Conflict Situations on Selected Roundabouts in the Czech Republic
Vladislav Krivda
Communications - Scientific Letters of the University of Zilina 2011, 13(3):77-82 | DOI: 10.26552/com.C.2011.3.77-82
The paper deals with video-analysis of conflict situations in road traffic and presents results of researches which were performed on selected roundabouts in the Czech Republic. This article refers to suitability of usage video-recording to analysis of behavior of participants of road traffic and also to monitoring of the danger places on the roundabouts. There are results of analyses which were performed in 2010 and also comparative analysis of conflict situations and possible traffic accidents.
Using Fast-Time Simulations for Designing and Operating Airport Terminals as Nodes of Intermodaltransport
Benedikt Badanik, Milan Stefanik, Martin Matas
Communications - Scientific Letters of the University of Zilina 2011, 13(3):83-90 | DOI: 10.26552/com.C.2011.3.83-90
Ever growing traffic in air transport with associated capacity constraints brings problems to air passenger flows at airports. There is strong link between quality of airport ground access system and airport terminal operations. However, this aspect remains underestimated in the development plans of many airports all over the world, which results in underutilization of both planed and existing infrastructure. In efforts for improvement, the higher level of synchronization and coordination between air and ground transport needs to be achieved. For this purpose, a computer model enabling to simulate passenger flows within airport's catchment area has...
Preventive Measures and Actions of the Police of the Czech Republic against Urban Violence
Martin Hrinko
Communications - Scientific Letters of the University of Zilina 2011, 13(3):91-95 | DOI: 10.26552/com.C.2011.3.91-95
The following article addresses the current problem of urban violence. The aim of the article is to outline the different preventive measures and actions of the Police of the Czech Republic taken in order to prevent urban violence. Moreover, various ways of documentation of illegal acts are presented. Having been the officer in charge during operations conducted against urban violence, the author also shares his practical experience.