bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental - theoretical study of the stress-strain state of cable-stayed-rod systems of the dome type
Authors: Akhmedov A D , Loseva I V , Kalmova M A 
Published: February 2021

Abstract
The problem of determining forces and displacements in a spatial hinge-rod system with missing links under static loading is considered. Equilibrium equations and geometric relationships are written in matrix form. The calculated equations are not linear. To solve the equations, a technique is proposed that is not associated with assumptions regarding the structure of the system or the nature of the load, based on the fact that the displacements obtained by solving the linear part of the equations can be significantly improved by interpreting the nonlinear terms as a load, under which the system can be considered as linear. To test the theoretical assumptions and preconditions, an experimental study was carried out on a model made at a scale of 1:30 of a natural design. The analysis of the results obtained is presented.
The regions of dynamic instability of a plate, the material of which obeys the hereditary low of viscoelasticity, at the second resonance
Authors: Kosheleva E 
Published: February 2021

Abstract
The problem of determining the side regions of dynamic instability of a rectangular plate, the material of which obeys the hereditary law of deformation, is considered. The solution of the integro-differential equation of vibrations of a plate loaded in its plane with constant and variable loads is considered. The solution used is a series with separated variables. An equation is obtained to determine the critical frequencies of even regions of instability. The influence of the parameters of the nucleus on the position of the second region of dynamic instability is investigated.
Reliability of a reinforced concrete frame building under earthquake
Authors: Mkrtychev O , Bulushev S 
Published: February 2021

Abstract
The research objective is performing probabilistic nonlinear dynamic seismic resistance analysis for the reinforced concrete building frame. The building design is compliant with SP 14.13330.2018 Construction Code. The LS-DYNA software was used for nonlinear dynamic analysis. A set of two-component accelerograms to be analyzed was generated. The set consists of 20 random seismic events with the specified expected values for the predominant frequency and the intensity. The structural response as random processes and values was studied. The resulting experimental response value distributions were fitted to distribution laws. The results showed that the K
1 factor accounting for acceptable damage to buildings and structures should be much larger than specified in the regulatory codes. It indicates that the seismic resistance of the building is insufficient in terms of the near-collapse failure criterion.
Natural frequencies of plates of medium thickness
Authors: Leontiev A N , Gorbunova T N , Missurin M R 
Published: February 2021

Abstract
A comparison is made of the frequencies obtained by the classical theory of thin plates and the refined theory of plates of medium thickness. Considered a rectangular plate with articulation along the contour. To determine the fundamental frequency, the Bubnov-Galerkin variational method is used. It is shown that with a relative plate thickness h/a = 0.2, the calculation refinement is approximately 15-20% for the values of the fundamental frequency of natural vibrations of a rectangular plate.
Analysis of the impact of shallow subway train traffic on urban development
Authors: Mitroshin V A , Mondrus V L 
Published: February 2021

Abstract
The article discusses the process of propagation of vibrations in a soil massif from a moving subway train. With the help of previously performed measurements of ground surface vibrations above a shallow metro line, it was found that the electrical insulating joint of rail strings is a source of increased vibrations when a train enters the station from a tunnel, which can lead to an excess of vibration acceleration levels in residential and industrial buildings limited by sanitary standards. The main types of wheel and rail defects are considered. The propagation of vibrations in unlimited space from a moving subway train in a tunnel, represented by an absolutely rigid body, loaded with dynamic action, taking into account the shock impact at the rail joint, has been studied. The dependences of the parameters of the wave field in infinite space and the displacement of the points of the tunnel on the frequency of the forcing action are found. It is noted that the parameters of the wave field decrease with an increase in the frequency of the external forcing action. The results obtained can be used to solve the problem of the propagation of vibrations in a confined space from moving subway trains.
Mixed finite element formulation for the nonlinear analysis of buckling behavior of truss under effects of temperature variation
Authors: Quyen V T B , Tien D N , Khuyen T M 
Published: February 2021

Abstract
This paper proposes a novel approach to consider the effects of temperature variability in the nonlinear finite element analysis of buckling behavior of truss system subjected to initial mechanical load. Generally, using displacement-based finite formulation the procedure for solving geometrically nonlinear problem of the truss system subjected to temperature load is required to implement the temperature deformation constraint depending on the incremental element length to the master stiffness equation. For escaping the mathematical difficulties of treating the additional constraint of temperature deformation this research proposes to formulate this problem based on mixed finite element formulation. The balanced mixed equation of truss considering temperature loading effect is constructed based on the principle virtual work with establishing the mixed matrix of truss element, which consists the element temperature deformation, considering large displacement. For investigating the effects of temperature variation to the nonlinear buckling behavior of truss this research develops the incremental-iterative algorithm for solving the nonlinear equation with incremental displacement and temperature by using Newton-Raphson technique. Based on proposed algorithm the calculation program is written for numerical investing the effects of temperature variation the buckling behavior of plan truss.
Investigation of shear connection between new and old concrete layers
Authors: Koteš P , Vavruš M 
Published: February 2021

Abstract
The structure and all its elements must be load-bearing, safe and serviceable. Due to time and external factors such as wind, thawing and freezing cycles, seismic activity, the structure of the concrete is disturbed and this leads to a reduction in the load-bearing capacity of the element. For vertical elements (columns), this usually means that the member´ strengthening must be used. The most common way of strengthening a concrete column is to use a new reinforced layer of concrete. In this case, great emphasis is placed on the contact between the original and the new layer of concrete. This article deals with two ways of surface treatment, such as notches and indents using different types of strengthening.
Investigation of the influence of heat protection characteristics of protecting designs on residential buildings heat storage capacity
Authors: Vytchikov Yu S , Chulkov A A , Golikov V A 
Published: February 2021

Abstract
The article presents the methodology of determining the heat storage factor of residential buildings heated by the central heating system. This calculation method is considered on the example of one-room corner apartment on the ground floor of an apartment building. The results of heat accumulation factor calculation are presented and the parameter changes depending on the value of normative multiplicity of air exchange and external air temperature are shown. The calculation of indoor air temperature after switching off the heating system was performed. The results presented in the article allow to draw a conclusion about the significant impact of natural ventilation during an accident on the heat network. The increase in air exchange in this case reduces the internal air temperature significantly. The obtained results should be used when choosing measures to ensure energy security of buildings and structures.
Passage of low temperature piping through the external wall
Authors: Leštach J , Ponechal R 
Published: February 2021

Abstract
The paper deals with the passage of the gas pipeline through the perimeter wall. The gas pipeline has a low temperature (the gas temperature drops significantly after the gas expansion in the regulator). When passing through the perimeter wall, the part of the wall near the internal surface will be significantly subcooled. Low temperatures in the building structure can cause local faults. The paper deals with the comparison of the course of temperatures and humidity of the passage of the gas pipeline in the protective tube with thermal insulation and without thermal insulation.
Shallow and deep foundations on permafrost soils at changing climate conditions
Authors: Stupivtsev A V , Cherkasova L I 
Published: February 2021

Abstract
The purpose of the work is to analyze the possible consequences of global warming on the state of permafrost and the issues of predicting the degradation of foundations during construction and design in permafrost regions. The study determines the principles and constructive solutions of foundations in areas with permafrost. From the presented options, the most rational one is selected. The analysis of observational data on the degradation of permafrost is given, on the basis of which the forecast of further degradation is built. Based on the research results, a rational method for erecting foundations in permafrost areas was determined taking into account the predicted degradation of permafrost.
Long-term vibration laboratory tests of sandy soils
Authors: Ter-Martirosyan A Z , Sobolev E S 
Published: February 2021

Abstract
The presented work examines the features of testing at the laboratory of the Moscow State University of Civil Engineering “Research and Education Center” Geotechnics “on a triaxial device with the ability to create dynamic loads (vibration stabilometer). Information on the course of cyclic tests of sandy soils is given, their analysis is carried out and formulated the main conclusions about the effect of the duration of vibration loading on the final stress-strain state of the soil mass.
Engineering and geological features of technogenic deposits and cultural layers in the territory of Samara
Authors: Vasilieva D , Baranova M , Maltsev A 
Published: February 2021

Abstract
The engineering and geological features of technogenic deposits in the territory of the city of Samara have been studied. Their features are revealed and a classification is carried out. The article presents the results of a petrographic study of samples taken at the archaeological site of Staraya Samara, Khlebnaya Square, carried out in 2019. The object represents cultural layers that were formed in the XVIII-XIX centuries at the site of the alleged location of the second Samara fortress. The studies were performed under a binocular microscope at an 8.75-fold magnification, in the passing light of a polarization microscope at a 72-fold magnification, and under a digital microscope at a 10-fold magnification. It has been determined that the pebble fraction is represented by quartzite and jasper flint, the sandy and silty fractions are angular quartz fragments with an admixture of undecomposed organic remains. Organic cultural layers, which reach 7-8 meters or more in the ancient part of the city, are especially powerful. Their presence is a limiting factor in modern urban construction.
Concept of management of the technolandscapes through the creation of innovative coal-watercoal clusters
Authors: Zommer T V , Chernyshev S N 
Published: February 2021

Abstract
Innovation should be at the heart of sustainable urban development. Innovations should become the basis for sustainable development of industrial and urban areas. A significant improvement in the quality of the environment can only be achieved through innovative technologies that should not degrade the environment. Coal mining at coal mining enterprises and coal burning at thermal power plants and in utility boilers are associated with a negative impact of economic activity on all geospheres. Therefore, it is important to ensure the rational use of natural resources and geo-ecological sustainability of industrial and urban areas through the introduction of innovative “green” technologies. In this regard, the authors of the article propose the concept of managing man-made and urban landscapes by creating innovative coal-watercoal clusters. The development of the concept of technolandscape management through the creation of innovative coal-watercoal clusters allows to increase the geoecological stability of industrial territories by significantly reducing the anthropogenic impact on the geosphere during coal mining and transportation. Development of scientific foundations, concepts and models of innovative coal-watercoal cluster includes the possibility of automatic control of innovative coal-watercoal technology, the concept of preparation and combustion of coal-watercoal slurry in housing and utilities boilers for the purposes of environmental management, energy and resources and reduce the negative anthropogenic impact on urbolandscape.
Map bases used for ecological stability assessment of land
Authors: Chromčák J , Seidlová A 
Published: February 2021

Abstract
The interest of land stability and its´ calculation due to the ecological stability and long term use of land as an entity is under pressure not only from ecological activists but the whole society at all. To calculate these kind of unknown values, which are interpreting many land possibilities and characters needed for many others calculations. That is the reason to find effective way to calculate the ecological stability index. The calculation of this index directly depends on character of area and its´ size. In Slovakia, there are many map bases with possible use for this purpose on whole territory. This paper is focused on the map base and their possibilities to be used.
Long Short-Term Memory (LSTM) neural networks in predicting fair price level in the road construction industry
Authors: Anysz H , Brzozowski Ł 
Published: February 2021

Abstract
Running a tender procedure in the construction industry a client expects receiving reasonable prices in the tenders. However, the market competition and the contractors’ will to win a contract to work out a profit, sometimes make the prices far from expected. They can be really low, almost impossible to be kept during the contract execution. Oppositely, the offered prices can be far above a client’s expectation. If they are extremely high, a client has to decide, to accept one of them (even bid-rigging is suspected), or to cancel the procedure. Nevertheless, cancelling a procedure means the considerably postponed the start of the construction. The analysis of almost 400 completed tender procedures (in the Polish road construction industry) and the market trends proved that unexpectedly high prices do not always have to point the collusive behaviours of the offerors. As aforementioned analysis is based on past cases, there is a need to propose the predicting tool, to help clients making decisions in the new tender procedures: to accept the high price as a market-based, or to reject all of the offers as a bid-rigging is suspected. The above-mentioned analysis are based on the simple moving average tool. For predictions the autoregressive tool is proposed – long short-term memory (LSTM) neural networks.
Structure and properties of polyepoxyurethane-containing isocyanurate polymers
Authors: Matseevich T A , Kejmakh M D , Askadskii A A 
Published: February 2021

Abstract
The modification of epoxyurethane-containing isocyanate polymers of a network structure was performed due to variations in the curing temperature and the ratio of diol, diisocyanate components and epoxy resin. When the reaction systems are cured below 100°C, the polymers contain a large number of flexible chain structures and pass into the rubbery state at ∼60°C. An increase in the processing temperature above 120°C leads to a significant change in the composition, which affects the properties of the resulting systems, the glass transition temperature of which increases in the limit to 225°C. An experimental change in the elastic modulus associated with an increase in the curing temperature from 80 to 200°C was found. At the processing temperature of 120°C, the Sol fraction content in the samples is decreased and the gel fraction is increased. Yield strength increases by 48%, modulus of elasticity by 107%, Brinell hardness by 40%, Shore hardness by 20 %. The glass transition temperature increases to 225°C.
Optimization of technological parameters of reinforced concrete production
Authors: Chiknovoryan A G , Mizuryaev S A , Yu Zhigulina A 
Published: February 2021

Abstract
The article presents the results of research in the field of improving the technology of production of reinforced concrete products aimed at optimizing the composition of concrete; quality control of concrete for strength, taking into account its uniformity; adjustment of the composition of the concrete mix taking into account the characteristics of the aggregates; improvement of the modes of heat treatment of concrete; stabilization of the geometry of freshly molded products, obtaining a smooth and high-quality surface of the products and reduction of marriage associated with spontaneous damage to freshly molded products. It is shown that rational modes of heat treatment of concrete, allows you to abandon the traditional scheme of heat treatment of concrete with steam and provide the necessary conditions for obtaining concrete with design physico-mechanical properties.
Influence of type and quantity of magnesium additive on the hardening process of alumina cement-based cement stone
Authors: Chumachenko N , Tyurnikov V 
Published: February 2021

Abstract
The greatest effect on increasing the residual strength of cement stone based on alumina cements in the temperature range of 800-1200 °C is achieved when replacing part of the cement with thermally activated metakaolin which is associated with the formation of secondary mullite. To intensify the strengthening process of mullite formation, the influence of various magnesium additives-mineralizers has been studied. The effect of chemically pure magnesium oxide, caustic magnesite and magnesium oxide hydration product calcined at 390 - 450 °C were investigated experimentally. The content of additives in compositions based on high-purity high-alumina cement was accepted in the amount of 0.5, 1 and 1.5 %. Experiments have confirmed the positive effect of magnesium additives on the process of hardening of cement stone, both during hardening and after heat treatment. It was found that the type of magnesium additive affects the hardening process. The highest strength after hardening and drying is obtained by using caustic magnesite as a mineralizer additive in an amount of 0.5 %. Exposed to high temperature, the best results are recorded when using a chemically pure magnesium additive.
Influence of mineral aggregate on asphalt pavement surface properties
Authors: Remišová E , Holešová N , Brna M 
Published: February 2021

AbstractThe road surface roughness is one of the factors influencing road safety. Therefore, the choice of materials and mixtures for the wearing course of pavement is important. The paper presents the results of research on the influence of the composition of asphalt mixtures on the surface parameters of PTV and MTD, which were analyzed according to the type of mixture, type of aggregate, and maximum aggregate size on laboratory-produced samples and samples with bitumen stripped surfaces. The skid resistance of SMA 11 and AC 16 mixtures were higher (PTV value 64.2 and 66.2) compared to AC11 and AC8 mixtures (PTV value 56.8 and 58.6) with all tested aggregates. After bitumen stripping from the surface, the PTV values of mixtures increased and the influence of the aggregate type and texture became more significant. To achieve better skid resistance properties, it is suitable to use coarse aggregate from andesite or granodiorite rocks (PTV value 67.0 or 65.8). Of the tested aggregates, limestone had the worst results (PTV value 63.3). Above all the portion of coarse aggregates, size distribution, and shape characteristics as shape index, angularity, determine the macrotexture of the surface.
Remote monitoring of road structures’ condition as a way to increase the durability of motorway
Authors: Dormidontova T V , Filatova A V 
Published: February 2021

Abstract
The calculations of road structures’ elements and the evaluation of reliability of data related to them are necessary for conducting justified and timely repair work, for forecasting the service life of road pavements, as well as for increasing the durability of motorway. Modernization of monitoring system, improvement of instrumental base structures, implementation of innovative methods in road construction allow carrying out more detailed research of road structures’ temperature and humidity conditions, analyzing their deformation stability under real-life conditions, and as a result, increasing measurement accuracy and reliability. Scanning devices used in the process of remote monitoring are characterized by tightness, high reliability and maintainability, their data is automatically read and transmitted to the server [1]. The input data obtained as a result of monitoring road structures’ condition are used to assess the impact of destructive factors of all elements of the system - the motor road, they are used to justify the application and selection of innovative materials and technologies. The obtained information allows imagining the processes that take place inside road structures and analyzing the peculiarities of external and internal factors’ impact on the service life and durability of the road.
Environment impact on the humidity change of beams from timber and glulam - experimental investigation
Authors: Leśko A 
Published: February 2021

Abstract
The paper relates to the humidity change in timber and glulam beams. Based on the literature moisture penetration into the wood phenomenon was briefly depict. The publication describes the carried out experiments: moisture measurement of glulam and timber beams in natural conditions. Results are presented in the form of graphs and photos on which cracks and warping of the samples is shown. Based on the literature and experimental results conclusions are drawn regarding the usage of glulam and timber beams in building industry.