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Open access

Libor Ižvolt, Peter Dobeš and Juraj Pieš

Abstract

The initial part of the paper briefly characterizes the present state of the track substructure dimensioning for the non-traffic load and the necessity of updating the design map of frost indexes IFd as a basis for dimensioning. A substantial part of the paper is dedicated to the method of evaluating the data provided by the Slovak Hydrometeorological Institute (SHMI), and determining the dependency of design air frost indexes IFd on altitude for the coldest winter period in the past 50 years. The paper conclusion presents the updated design map of frost indexes and the assessment of the importance of its updating in terms of the track substructure dimensioning methodology for the non-traffic load.

Open access

Rositsa Petkova-Slipets and Penka Zlateva

Abstract

The paper presents the results from a study of the thermo-physical properties of a new synthetic acrylic polymer used as material in road construction and as concrete on its basis. For the purposes of the study, the Modified Transient Plane Source Method (MTPS) was used. Data on the following thermal characteristics were obtained: thermal conductivity coefficient, thermal effusion, thermal diffusion and specific thermal capacity. A comparative analysis was made with the analogous indicators of conventional petroleum bitumen and asphalt concrete. The results of the study can be used for a more precise calculation and prognosis of temperature deformations and thermal stresses, as well as the crack propensity at low temperatures in asphalt concretes.

Open access

Marek Kurnatowski

Abstract

The article describes the results of tests carried out to determine the measurable effect of vibrations on the accuracy of measurements with an automatic precise leveller. It contains specification of the research station created to examine the case and description of factors affecting the measurement results. The multi-frequency vibrations were forced on a leveller during measurements and calculated mean errors for each frequency analysed. The range of frequencies for which the measurement was possible was estimated. The obtained results can be helpful in the engineering measurements designing, especially in industrial areas, where vibrations are an inseparable element of the environment.

Open access

Zeynab Mohammadian and Majid Shahbazi

Abstract

Housing is a widespread and complex issue with a variety of dimensions. First, housing was considered as a physical location and as a shelter and basic necessity of the households, but today the concept of dwelling as the place that provides all the services and facilities necessary for a better life of the family has been created. One of the issues discussed at many conferences and in general in the scientific community is the definition of sustainability in the psychological point of view, along with the ways to introduce this concept into the architecture and human habitat environments. This research first begins with the main question about how the concept of sustainability can be found within the scope of housing. Then existing resources search is done and accessible projects are analyzed and the weaknesses and strengths of traditional architecture and contemporary architecture are compared. Finally, the relationship between the definitions of three concepts: dwelling, sustainable design and traditional Iranian architecture was discussed. At the end, the sustainable design that is also appropriate to the Iranian culture was presented.

Open access

Veronika Valašková and Jozef Vlček

Abstract

This article illustrates the applicability of the Finite Element Method (FEM) in the analysis of multi-layer concrete pavement systems subjected to tire loading of a heavy vehicle. For the purpose of simplifying the interaction of the interaction system, it is appropriate to divide the system into two separate independent subsystems, the vehicle and the pavement. For this reason, 2-dimensional interaction model of the contact vehicle-obstacle and 3-dimensional FEM model of the concrete pavement were created. A several constitutive material models, such as linear elastic model, are applied in the analysis to describe the behaviour of the pavement structure. The numerical results from the first computational model can be used as the input for the second calculation phase. The concrete pavement represents a standard pavement, which is used for the regular road structures in road engineering. FEM modelling of the pavement can be used for the direct estimation of the pavement response without performing time and cost expensive field experiments. Calculations were performed in software ADINA using FEM method.

Open access

Mária Kúdelčíková and Eva Merčiaková

Abstract

In structural dynamics models of mechanical oscillator and vibration analysis are of great importance. In this article motion of mechanical oscillator is modelled using second order linear autonomous differential systems. Stability of such 1 DOF models is investigated with respect to the coefficients of systems. Phase portraits for various cases are displayed and the character of fixed points is described.

Open access

Mariusz Maślak and Doncho Partov

Abstract

The oldest man-made false-arch stone bridges are presented and briefly described. It is shown that this construction technique was based on the experiences of the first builders, formed at the junction of ancient Egyptian, Mycenaean as well as Assyrian and Babylonian cultures. Arches in such bridges have not yet been constructed in a classical manner, i.e. one that was later prevalent by the Romans, but these were only the primitive arch-like structures, with a false needle vault, that were shaped mainly by corbelling. This type of the structure, if it was used in bridges, turned out to be much more stable than the well-known at that time and commonly used in gateway passages oval “true-arch” built from sun-dried mud bricks.

Open access

Wanda Kokoszka

Abstract

Mass movements and floods are natural hazards posing a threat to the environment and bring significant economic losses. The flooding and landslide are risks in the municipalities of south-eastern Poland. Long-lasting rains cause initialize process of landslides on the slopes above the river valley, as well as flooding of local infrastructures (buildings, roads, railway tracks) located near water courses. Monitoring of geotechnical and hydrological parameters of the area is the base for the prognosis, as well as the risk assessment associated with them. So, in the paper highlights the issue of the consistency of monitoring and warning systems for these two threats. For landslides work SOPO - System Guards Against Landslides. Hydrogeological bases are defined for floodplains as The Computer System of the National Guard - ISOK. However, notable is the lack of integrity of both systems. In this paper a proposal to determine the overall risk for both threats in case of a single building is presented.

Open access

Filiz Ersoz, Taner Ersoz and Muhammet Soydan

Abstract

Construction sector has an important place in Turkey’s economy. Real estate sales for the sector are increasing in parallel. However, the purchase cost is also important for those who are willing to buy a real estate. In the acquisition of real estate, factors such as size, location and age of the house are taken into consideration. The aim of the article is to conduct research on factors affecting real estate values by data mining. In this study, the most important variables that determine the value of the real estate have been investigated by data mining methods. The research has been carried out in Karabük and the variables determined according to the opinions of real estate experts. As classification methods, CHAID and C&RT algorithms have been used. It has been evaluated that both algorithm estimation results can be used. Within the framework of the study, the variables that have the most impact on the unit price have been determined, such as the size of the real estate, the distance to the city centre, the popularity, and the age of the building. The use of advanced technologies, such as statistical modelling and machine learning in real estate valuation and automatic value estimation, is of importance in determining the real value of the real estate.

Open access

Robert Mańko

Abstract

In the paper, the backwater curve ranges at the mouth of the Odra River with changing boundary conditions were analysed. The aim of the study is to determine which boundary condition, i.e. stage of lower cross-section or flow in upper cross-section, has a greater impact on the formation of the backwater curve at the mouth of the Odra River. Due to the complicated system of the Lower Odra River network (Międzyodrze and Dabie Lake), the analysis takes into consideration a section of the Odra River from a weir in Widuchowa upwards, thereby accepting as an axiom that the cross-section in Widuchowa is within the range of sea impact, regardless of other hydrological conditions.