bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the towing properties of construction vehicles
Authors: Mukhametshina Rumiya , Makhmutov Marat 
Published: August 2020

Abstract
This article studies the ways to increase the towing properties of propulsors and the patency of wheeled vehicles.
The characteristics of the machines running systems significantly affect the technical level of the unit. The paper justifies the advantages of wheel dwellers over caterpillar ones. The advantages include small specific metal consumption and the possibility of usage on the roads. Wheel tractors provide the best working conditions for the driver and maintenance personnel.
Analysis of the calculated coefficients shows a significant scatter of values, which causes difficulties in the calculations. For this, it is necessary to know the values at each interaction of the tractor propulsor with the soil. The same slippage values can be obtained with different values of the coefficients. The task is simplified if these dependencies have one coefficient.
The paper obtains a model for a more complete assessment of the towing properties of wheel and tracked vehicles with a minimum number of experimental coefficients, which makes it easily applicable for engineering calculations.
Experimental studies of the working process of compaction of sand with a vibrating plate
Authors: Sakhapov Rustem , Kadyrov Adil , Gatiyatullin Mukhammat , Zemdikhanov Minsur 
Published: August 2020

Abstract
The paper investigates the process of compaction of a sand layer with a manual vibroplate under various technological conditions. The moisture content of the sand layer was previously determined in accordance with the accepted methodology. Then, as a result of preliminary experiments, the authors selected the limits of variation of some technological parameters of the vibroplate. To reduce the volume of experiments and increase their accuracy, the authors used an almost rotatable three-level non-factorial plan. The obtained experimental data were processed using the Statistika.exe software. As a result, the obtained mathematical models describe the dependences of the density of the sand layer on the mass of the additional load and the speed of the vibroplate, as well as on the frequency of rotation of its unbalanced shaft. The results are presented in the form of three-dimensional graphs and equations describing the compaction process. The paper analyses the research results and conclusions. They will allow to determine some optimal technological parameters of the vibroplate during the compaction of the sand layer.
The critical forces in the weak ground under the influence of technogenic relief
Authors: Burlakova A M , Malova N A , Filatov V V 
Published: August 2020

Abstract
The initial critical force that the ground is exposed to from the weight of a structure is one of the main characteristics of the “structure-ground environment” system. A significant part of grounds are classified as weak, and the strain modulus value does not exceed 5 MPa. These soils have a weak load-carrying capacity and they are significantly deformed by the weight of the structures and the static load of technogenic relief. The theory and methodology of determining the initial critical force and its maximal action depth for various two-dimensional technogenic land forms, the force diagrams of which are described by trapezes and triangles of various types, are considered. The models grounds considered herein are a homogeneous elastic half-space or horizontally layered strata on the surface of a homogeneous elastic half-space. The nomograms of the relations of the initial critical force and its maximum depth of action to the ground’s physical and mechanical properties are attained. The identified relations are quasi-linear and the value of the initial critical force increases with an increase in the ground’s physical and mechanical parameters. The presented nomograms significantly simplify the calculation of the initial critical force in the ground.
Analytical and numerical solution of the stress-strain state of sleeper foundations
Authors: Glushkov Alexey , Glushkov Vyacheslav , Glushkov Ilya 
Published: August 2020

Abstract
The article presents the results of numerical modelling of strip sleeper foundations. The analysis of the influence of the distance between the sleepers in the conditions of a two-dimensional problem. As a comparison, the results of the calculation of the analytical corner points method is presented. The results of the study of sleeper foundations with different distances between sleepers up to 3b are shown. The analytical solution shows the distribution of stress over depth when changing the size of sleepers, distances between sleepers. An analytical solution for the distribution of vertical displacements over depth is obtained. The results of the numerical solution show the components of stress and strain at different distances between sleepers, the dependence of precipitation on the applied pressure and the distance between sleepers. These studies are confirmed by the results of experiments of various authors. Designs of sleeper foundations are implemented in the construction of buildings and structures, which reduce the cost of the zero cycle, reduce the material consumption in comparison with standard solutions. The article is of interest to specialists in the field of soil mechanics, geotechnics, and foundation engineering.
Steady-state and unsteady-state moisture regime of enclosing structure
Authors: Gagarin V G , Khavanov P A , Zubarev K P 
Published: August 2020

Abstract
This paper describes the moisture transfer problems of enclosing structures which are crucial in modern construction industry. In terms of current condition of science, researchers do not know the moisture transfer law in capillary-porous materials, so they need to work with a variety of mathematical models. We developed the new steady-state and unsteady-state formulation of mathematical models based on moisture potential F, which takes into account water vapour and liquid movements uniformly. It is vital to understand whether we can use steady-state moisture transfer mathematical model in a design engineer work or we must use the unsteady-state one, so we make a comparison between them for a single-layer aerated concrete wall. We compare moisture behaviours of the steady-state and unsteady-state processes in two ways: comparison of the moisture distribution in the thickness of the enclosing structure during maximum moisture accumulation period and comparison of the average moisture of the wall during a year. It was found that the solution of the unsteady-state equation of moisture transfer gives significantly more possibilities than the solution of the steady-state equation of moisture transfer. As a result, we recommend to use the developing unsteady-state mathematical model to predict the moisture regime of enclosing structures.
The position of the maximum wetting plane in building enclosing structures
Authors: Gagarin V G , Khavanov P A , Zubarev K P 
Published: August 2020

Abstract
We investigate the maximum wetting plane position in two enclosing structures: the first enclosing structure is with aerated concrete base and mineral wool insulation, the second enclosing structure is with aerated concrete base and expanded polystyrene insulation. Two fundamentally different cases of the maximum wetting plane are obtained. For the enclosing structure with mineral wool insulation, the maximum wetting plane is located between the insulation and the external stucco. It was found that when the indoor climate parameters or thicknesses of layers change, the position of the maximum wetting plane does not change. For the enclosing structure with expanded polystyrene insulation, the maximum wetting plane is located inside the insulation layer. It was found that when the indoor climate parameters or thicknesses of layers change, the position of the maximum wetting plane also changes. In terms of application result for calculation, an enclosing structure with aerated concrete base and expanded polystyrene insulation is significantly more sensitive to climate parameters than an enclosing structure with mineral wool insulation. It becomes possible not to obtain the maximum wetting plane position in encloses with mineral wool, and to use described calculated position, therefore, it can save time of engineers during the moisture regime calculation.
Floating slab track efficiency tests in Moscow underground
Authors: Smirnov Vladimir 
Published: August 2020

Abstract
The article deals with field tests of a floating slab track (FST) – a railway track structure used in Moscow underground. The upper track structure to be tested was erected in 1977 and consists of a concrete track slab with embedded wooden sleepers, rails R50 with “metro” fastenings and a series of rubber isolators, that support the concrete slab and transfer all the loads down to the tunnel casing. The aim of the test is to get substantial experimental data and understand its static and dynamic behaviour in order to use in further development and verification of FST’s design models. During the test under moving trains different load parameters are acquired: dynamic vertical and horizontal forces, rail & slab deflection and acceleration at different points on the slab and tunnel casing. On the basis of this multifactorial survey, verification data is acquired and weak points of the FST are investigated.
Evaluation method of technical condition façade systems
Authors: Shubin L I , Rimshin V I , Truntov P S , Suleymanova L A 
Published: August 2020

Abstract
The technique of monitoring the conditions of a fçgade system as part of the scientific and technical support of construction. The building demands an increased level of responsibility. Facade systems “ZIAS-100.02” with cladding with fiber cement slabs and “ZIAS-100.02” with cladding with concrete slabs are used during the construction. Monitoring of the system is carried out in order to verify the compliance of the facade fencing with the requirements of design documentation, applicable standards and requirements, as well as to determine and evaluate the actual condition of the facade system. Selective tests of anchor dowels of sizes 10x135 and 10x100 mm used in hinged facade systems were completed as part of the monitoring. The tests were carried out after a visual inspection of the facade system structures. During the tests, the ONIKS-1.VD.050 material strength meter was used. Anchor dowels were pulled out from two types of walls. The first type of walls is made of foam concrete blocks, the second type of monolithic reinforced concrete. The results of tests for two types of walls are presented. A variant of processing the individual results of the breaking load values obtained during the testing of anchor dowels of the facade system is also shown.
Rational design solutions of ensuring the walls of tanks stability to the action of transverse loads
Authors: Mushchanov Volodymyr , Tsepliaev Maxim 
Published: August 2020

Abstract
The article considers the task of an integrated approach to the study of the rationality of strengthening the cylindrical walls of large volume tanks with stiffening rings under transverse loads. Based on the results of computational studies, the principles of placement and rational boundaries usage of stiffening rings for vertical cylindrical tanks of various volumes are determined. The results were obtained for ideal shells and for cases of the presence of a typical geometric wall defect in the form of the angularity of a vertical weld. To validity the reliability of the results obtained, an experimental verification of the numerical model was carried out.
Reinforcement of brick structures with carbon fiber
Authors: Gonshakov N G , Gonshakov A G , Aleksiievets I I 
Published: August 2020

Abstract
Based on the analysis of approaches to reinforcing the brick masonry structures, the advantages of carbon fiber as a reinforcing component are presented. Methods for calculating brick structures reinforced with carbon fiber under central and eccentric compression are proposed. These methods allow determining the longitudinal force taking into account the calculated compressive resistance of the masonry, the masonry working conditions and the influence of long-term load, as well as the coefficient of the masonry surface reinforcement at the reinforced wall. The schemes of strengthening the wall with vertical canvases and at the same time vertical and horizontal carbon fiber canvases are considered. Depending on the direction of the eccentricity of the load application, methods for calculating the strength of reinforced masonry under the action of a moment in the masonry plane and from the wall are developed. The ultimate deformations of carbon fiber are estimated taking into account possible options for the destruction of masonry reinforcing elements.
The effectiveness of structures combined from elements of various materials united by bonds consistent with the SSS of the connected elements
Authors: Shmidt Alexander B 
Published: August 2020

Abstract
Various constructions are considered, combined over sections from various structural materials, such as engineered wood (solid, glued, reinforced, plywood, LVL, CLT, etc.), metal of various grades and alloys, concrete, reinforced concrete, fiber-reinforced concrete, etc., which are combined with the help of various elements (connections) in terms of material, form and work. Examples of various composite structures in which structural elements are connected by bonds of different types are given. The analysis of the pairing of elements of such combined (or composite) structures shows that the most effective structures are those in which the connecting elements are adaptively (self-adapted) aligned with the stress-strain state (SSS) of the mating elements. Following this rule (principle) will allow you to avoid mistakes in the design of combined structures, choose reliable and effective means of connecting structural elements. The same can be attributed to the elements of amplification or reconstruction. A brief description of the patented design with adapted connections installed in two mutually perpendicular planes is given.
Strength and deformations of high-strength concrete under short-term heating conditions up to + 90°C
Authors: Korsun V I , Khon K , Ha V Q , Baranov A O 
Published: August 2020

Abstract
The results of experimental researches of short-term heating effect up to +90°C on strength, modulus of elasticity and ultimate strains under axial compression of modified high-strength concrete of C70÷C90 classes were presented. The concrete was obtained with the modifier application MB 10-50C. Temperatures of tests − +20°C; +50°C; +70°C; +90°C. Lifting speed of temperature during heating − 15°C/h. The decrease of concrete strength under axial compression was installed in short-term heating conditions up to +50°C; +70°C; +90°C respectively 20%, 23%, 28% by comparison with tests at the normal temperature. Meanwhile, the modulus of elasticity decreased 18%, 20% and 22% respectively. The ultimate compressive strain of concrete increased 15%, 9%, 11% respectively at the same temperatures. This work was carried out within the frameworks of the grant of FNI Ministry of construction of Russia and RAASN on the topic 7.4.15-18 «Fundamental scientific researches of the elevated temperatures’ influence up to 200°C on the characteristics of physical-mechanical and rheological properties of modified high-strength concrete of C70÷C90 classes».
The calculation of creep deformation of high-strength concrete in relation to the conditions of exposure to elevated temperatures
Authors: Korsun Vladimir , Shvets George 
Published: August 2020

Abstract
The results of generalization and analysis of experimental research data on the creep deformation of heavy concretes of medium and high strength under conditions of elevated temperatures up to + 200°C are presented. It is shown that the experimental data of some authors are difficult to compare due to the significant influence of differences in test methods. All other things being equal, modern high-strength modified concrete is characterized by lower creep deformations in comparison with ordinary medium-strength concrete. It is shown that the ultimate values of the specific creep deformation of high-strength concrete at a long compression level of ήσ=0.5 under conditions of heating to 200°C are lower, on average, by 45% in comparison with similar characteristics for ordinary concrete of medium strength. With an increase in the level of long-term compression from ήσ=0.2 to ήσ=0.5, the specific creep strain of ordinary concrete of medium strength increases in the temperature range from +20°C to +200°C on average, by 28%, and in high-strength concrete with an increase in the level of long-term compression with ήσ=0.3 to ήσ=0.6, an increase in the similar characteristic was about 40%. The specific creep strain of high-strength concrete at a long compression level of ήσ=0.5 with an increase in the heating temperature from +20°C to +200°C increases by 2.8 times, and for medium-strength concrete − by 3.1 times. The massiveness of the samples (scale factor) can be taken into account using a parameter such as the modulus of the open surface. With an increase in the modulus of the open surface with a decrease in the mass of the samples, the creep strains of high-strength concrete increase at all heating temperatures. In relation to simplified engineering calculation methods, the recommended values of creep coefficients for concrete of classes B60 – B90 are proposed. In the development of concrete deformation models, approximating expressions have been developed that allow reliably assessing the creep strains of high-strength concrete of classes up to B90. The method relationships are based on the theory of aging and take into account the influence of the heating temperature, the duration of its action, the influence of the nonlinear component of creep, and the scale factor. The temperature and duration of heating before and after application of the load are taken into account using the functions of the reduced time. Satisfactory compliance of the calculated values of creep deformation of high-strength concrete with experimental data is shown.
Dynamic additional loading of the frame of a multi-story building after the failure of one of the structures
Authors: Fedorova N V , Vu N T , Iliushchenko T A 
Published: August 2020

Abstract
A calculated model of a building frame fragment is presented for calculating the dynamic additional loading of structural elements in the zone of possible local destruction after the failure of one of the structures. To model such a fragment, a substructure isolated from a structural system of the building frame was used in the form of a two-span statically indeterminate continuous beam under various boundary conditions on the extreme supports, loaded with a specified design load. The sudden removal of the middle supporting column of the substructure is modelled by reducing to zero for some short-time the internal force in this column, obtained when calculating the entire frame of the building. The use of level calculated schemes and analytical description of the movement of reinforced concrete substructure with variable stiffness due to cracking for determining the dynamic additional loading of frame elements of a multi-story building after the failure of one of the structures allows to define the parameters of the dynamic response of the substructure and simulate in more detail the zones of possible local destruction of the building under the considered special action. The developed algorithm for calculating physically and structurally nonlinear reinforced concrete systems can be used for the calculated analysis of the frame of multi-story buildings when designing their protection against progressive collapse.
Force resistance of steel columns of industrial buildings with corrosion damage
Authors: Buzalo N , Gontarenko I , Chernikhovski B 
Published: August 2020

Abstract
It is proposed to use the computer modeling results to assess the degree of operational suitability and the possibility of further safe operation of building metal structures of industrial buildings and structures that have received corrosion damage, and to predict their reliability at various stages. The force resistance of steel eccentrically compressed columns, taking into account corrosion wear, was determined in SCAD PCS using a linear model of universal finite elements for shell calculation, as well as taking into account physical and geometric nonlinearity in ANSYS PCS. The authors obtained isofields and isolines of various components of displacements and stresses for the linear model, isofields of main stresses per Mises-Hencky, and displacements for the model, taking into account changes in the elastic material modulus with increasing stresses beyond the limits of proportionality. Verification of the computer modeling results for compliance with reality was performed through an experiment. To perform the study, it is possible to evaluate the power resistance eccentrically compressed structures subject to corrosion, to determine the influence of corrosion factors and the locations of elements on the bearing capacity, to give recommendations on ensuring the reliability of the operational characteristics of structures when diagnosing the technical condition of buildings.
Mathematical modeling of transition processes due to a change in gas consumption at the ends of the inclined section of the gas pipeline
Authors: Khujaev I , Shodmonova G , Mamadaliyev X , Aminov X 
Published: August 2020

Abstract
The paper presents a solution to the problem of the gas-dynamic state of an elementary section of a gas pipeline with variable input and output mass gas outflows, which is obtained by the method of separation of variables. The quasi-one-dimensional mathematical model of pipeline transport of real gas takes into account factors such as friction, gravity and the local component of the inertia of the gas. By introducing the mass flow rate and averaging the velocity in the quadratic law of resistance, the autonomous equations of the telegraph equation with respect to pressure and mass flow are compiled from a system of equations. Taking into account possible abrupt changes of the unknowns in time and distance, the solution is sought in the form of functional series. The demonstrativeness of this method lies in the fact that the perturbation frequencies relevant to the parabolic and hyperbolic types of equations and the intermediate variant are distinguished. A description is given of a general method for solving the problem when temporary changes in the gas mass flow rate are set at the ends of the section. The exact solutions of mass flow rate and hydrostatic pressure are obtained for the case of a spasmodic change in mass flow rate at the boundaries of the site with a constant slope from the horizon. Numerical results related to the case of instantaneous closure of the output section of a linear section are presented. The results of the work are useful for assessing the energy intensity and reliability of gas pipelines in conditions of large diameters, high working pressures, and also when the gas pipeline is laid along a relief line.