75504 2712-8172 Magazine of Civil Engineering 1 85 2019 1-145
RAR RUS 3-14 57194623014 South Ural State University Baiburin Albert abayburin@mail.ru
76, Lenin prospekt, Chelyabinsk, Russia, 454080
 South Ural State University Rybakov Mikhail rybakov.mixail@mail.ru
76, Lenin prospekt, Chelyabinsk, Russia, 454080
 M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 Heat loss through the window frames of buildings The object of investigation is window frames of buildings since they are critical zones in terms of thermal insulation. It was studied how the properties of window frame affect the change in heat flow and temperature fields. It was analyzed the heat loss that depends on a range of structural features of a window frame, such as geometrical, thermal and physical properties of walls, windows, lintels, and joints. An experiment was designed, computer simulation and laboratory tests were conducted. Eight different types of frame units were analyzed. Their finite-element models in the ELCUD software was developed. The laboratory tests proved the adequacy of finite-element models. The comparative results obtained from tests and numerical models were in consistency. We conducted a full factorial experiment and excluded insignificant factors using statistical analysis. Mathematical models of the joint effect of these factors were developed. A detailed analysis of the join effect of factors on the heat loss through the window frame was performed. The results can be used for the energy classification of buildings in use. 10.18720/MCE.85.1 buildings windows window frame energy efficiency thermal insulation heat loss heat transfer factors mathematic simulation https://engstroy.spbstu.ru/article/2019.85.1/ 01.pdf
RAR RUS 15-27 University of Transport and Communications Thai Thi Kim Chi chittk@utc.edu.vn
3, Cau Giay, Lang Thuong, Dong Da, Ha Noi, Vietnam
 Numerical simulation of the turbulent flow over submerged bridge decks Today climate change is one of the most significant threats and global issues that should be concerned. It causes the increased number of natural disasters such as hurricanes, storms, typhoons and floods. Under these critical hydrological conditions, transportation infrastructure includes bridges easily got submerged, damaged and lead to its failures. Evaluation of bridge stability, hydrodynamic forces acted to bridges and understanding the complex flow behavior in particular during and after flooding plays an important role to estimate the probability of failure risks for existing bridges and optimal design of future bridges. In the present paper, the turbulent flow with high Reynolds number over a fully submerged bridge deck with various length-to-thickness ratios is numerically investigated by using ANSYS FLUENT. The blockage and submergence ratios are defined as 0.23 and 2, respectively. The realizable k–ε model and volume of fraction (VOF) is applied to predict the complex water surface profiles over the bridge deck and turbulence characteristics including backwater effect upstream of the bridge. Effects of the aspect ratio to the drag coefficient are studied. 10.18720/MCE.85.2 bridge deck drag coefficient flow turbulence numerical simulation https://engstroy.spbstu.ru/article/2019.85.2/ 02.pdf
RAR RUS 28-38 57199850188 0000-0002-2279-1240 Far Eastern Federal University Fediuk Roman roman44@yandex.ru
8. Suhanova St. Vladivostok, st. Octyabrskaya. 690950. Russia
 V.G. Shukhov Belgorod State Technological University Lesovik Valeriy naukavs@mail.ru Far Eastern Federal University Liseitsev Yuriy gera210307@ya.ru
8, Suhanova St. Vladivostok, st. Octyabrskaya. 690950. Russia
 57194347544 Far Eastern Federal University Timokhin Roman gera210307@yandex.ru
8. Suhanova St. Vladivostok, st. Octyabrskaya. 690950. Russia
 East Siberia State University of Technology and Management Bituyev Aleksandr office@esstu.ru
Ulan-Ude, Russia
 East Siberia State University of Technology and Management Zaiakhanov Mikhail roman44@ya.ru
Ulan-Ude, Russia
 Far Eastern Federal University Mochalov Aleksandr captainvmf@yandex.ru
8. Suhanova St. Vladivostok, st. Octyabrskaya. 690950. Russia
 Composite binders for concretes with improved shock resistance The qualitative and quantitative composition and properties of the initial materials, composite binders and concrete samples were studied. Optimal compositions of concrete for protective structures that provide the maximum static and dynamic strength characteristics are selected. In this case, the effect of increasing the shock endurance increases to 6 times. It has been found that concretes with a small number of defects, high packing density and uniformity, good adhesion between the aggregate and cement stone, an increased ratio of static tensile strength to static compressive strength Rtens / Rcompr and ductility have the best resistance to dynamic impact. It is proved that this ratio can be increased, in the case of the use of dispersed reinforcement of concrete (so-called fibrous concrete). In experimental studies on penetration of both unreinforced and fiber-reinforced concrete slabs, it was noted that samples of unreinforced concrete were completely destroyed in large and small pieces, while samples of fiber-reinforced concrete were not completely destroyed, and only through penetration at the impact site was observed; that is, fibrous concrete has the best impact resistance. These results can be applied to the design of various special structures, such as protective structures of civil defense and emergency situations, concrete structures of nuclear power plants, etc. 10.18720/MCE.85.3 self-compacting concrete rice husk ash pozzolanic materials shock resistance fresh properties mechanical properties https://engstroy.spbstu.ru/article/2019.85.3/ 03.pdf
UNK RUS 39-50 Hubei Business College Pei Guihong 570769297@qq.com
Hubei province,China
 Southwest Petroleum University Zhang Qiuyi luomusanchang@qq.com The critical ventilation velocity for transverse double fires in tunnel The critical velocity of longitudinal ventilation is one of the most important parameters in tunnel fires. Most previous studies simulated fire scenarios in which only one fire source exists in the tunnel. However, the critical velocity will change under the condition of transverse double fires. In this study, the critical ventilation velocity under the transverse double-fire condition compared with the single fire source was analyzed by using the Fire Dynamics Simulator (FDS). The results show that the smoke movement for transverse double fires in the tunnel is affected by both the buoyant force and the shear stress of the sidewalls. As the distance between the double fires increases, the critical velocity decreases first, then increases and eventually decreases. When the double fire sources are both near the side walls, the critical velocity is approximately equal to the critical velocity for adjacent double fires at the center. Finally, relations between the influence coefficient of distance and the dimensionless transverse distance as well as correlations between the critical ventilation velocity with and without distances for double fires were developed. The presented correlation can provide reference value for smoke control and personnel evacuation in case of tunnel fires. 10.18720/MCE.85.4 tunnel fire numerical simulation transverse double fires critical velocity https://engstroy.spbstu.ru/article/2019.85.4/ 04.pdf
RAR RUS 51-58 0000-0003-2533-9732 National Research Moscow State Civil Engineering University Samarin Oleg samarin-oleg@mail.ru The periodic temperature oscillations in a cylindrical profile with a large thickness A hollow cylinder with thick walls is one of the most complex objects to calculate the unsteady temperature field, so this field is the least studied. However, such objects are found in many modern constructions of systems of generation and distribution of heat. In the proposed work it deals with the study of propagation of temperature waves in the wall of the hollow cylinder with harmonic temperature change of external environment arising from its diurnal fluctuations. The approximate analytical solution is presented by separation of variables in the complex domain with the use of cylindrical functions. The algorithm of calculation of temperature fields numerically is shown using an explicit finite-difference scheme of high accuracy in conditions of cylindrical symmetry with boundary conditions of the first kind. The results of calculations according to the considered algorithm, depending on the time since the start of heat exposure and their comparison with the analytic solution are given for its implementation. Calculated radial profiles of the temperature in the cylindrical wall within the temperature waves and the analytical approximation relations for the description of its damping coefficient are presented. The results are compared with the existing analytical solution in rectangular coordinates and it is marked that they have some differences but the common results are found regardless of the material and geometry of the cylinder, as well as of temperatures of inner and outer environment. Presented dependences are invited to apply for the analytical evaluation of the temperature amplitude on the inner surface of the heated cylindrical structures that will allow the use of engineering methods to verify compliance with industrial safety requirements. 10.18720/MCE.85.5 hollow cylinder thermal conductivity equation Hankel function finite-difference scheme temperature wave cylindrical symmetry damping coefficient civil engineering building construction industry https://engstroy.spbstu.ru/article/2019.85.5/ 05.pdf
RAR RUS 59-70 St. Petersburg State University of Architecture and Civil Engineering Korneeva Elena linka360639020@yandex.ru
2-nd Krasnoarmeiskaya St. 4, 190005 St. Petersburg, Russia
 M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 Peter the Great St. Petersburg Polytechnic University Dontsova Anna anne.dontsoova@gmail.com
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
 Mechanical properties of the Crimean limestone, treated with material based on silicic acids The paper describes shell-limestone treatment with stone strengthener Oxal NK 100. Aging impairs the mechanical characteristics of the stone and reduces its bearing capacity. The purpose of the study was to investigate the efficiency of the stone-strengthening composition Oxal NK 100. The composition is supposed to reduce water absorption and strengthen the stone. Cube samples of the Crimean shell-limestone were used. Several testing operations were made to reveal such specifications as absorption of water, compression capacity, freeze-thaw resistance, and porosity of the material. Tests were done on two kinds of samples: treated and non-treated. The results of the study indicated an improvement of mechanical properties of treated stone, compared to non-treated rock samples. The study proved the efficiency of the use of stone-strengthening materials for construction and restoration with shell-limestone. 10.18720/MCE.85.6 limestone shell limestone treatment restoration durability consolidation https://engstroy.spbstu.ru/article/2019.85.6/ 06.pdf
RAR RUS 71-91 7003880429 Institute of Mechanics and Seismic Stability of Structures Academy of Sciences of the Republik of Uzbekistan Sultanov Karim sultanov.karim@mail.ru
100125, Tashkent, 31, Dorman street
 Institute of Mechanics and Seismic Stability of Structures Academy of Sciences of the Republik of Uzbekistan Loginov Pavel lopavi88@mail.ru
100125, Tashkent, 31, Dorman street
 Institute of Mechanics and Seismic Stability of Structures Academy of Sciences of the Republik of Uzbekistan Ismoilova Sabida ismailova.sabida@mail.ru
100125, Tashkent, 31, Dorman street
 Institute of Mechanics and Seismic Stability of Structures Academy of Sciences of the Republik of Uzbekistan Salikhova Zulfiya zulfiya6665@gmail.com
100125, Tashkent, 31, Dorman street
 Quasistaticity of the process of dynamic strain of soils Mechanical characteristics of soil under static and dynamic strains are determined experimentally. Their accuracy and reliability depends on quasi-static nature of strain process in soil. The independence of experimental results on the wave processes is ensured. Laboratory devices of dynamic loading (DDL) have been used to determine the laws of dynamic strain and mechanical characteristics of soil. The quasi-static nature of strain process in soil on DDL is achieved solving the wave problem corresponding to experiment. Plane wave propagation in soil is considered; its statement is adequate to experiment on DDL. To describe the dynamic strain of soil, the G.M. Lyakhov elastic-viscoplastic model has been adopted. The system of differential equations in partial derivatives of hyperbolic type, describing the wave process, has been solved by the method of characteristics and finite difference method in an implicit scheme. The changes in wave parameters over time for different sections of soil layer have been obtained by numerical solution. The effect of layer thickness on wave parameters and on quasi-static process is shown by experiments. Quantitative and qualitative influence of mechanical characteristics of soil on wave parameters is determined. Analyzing results, it has been established that the main factors determining the quasi-static process are the parameters of dynamic load and the thickness of soil layer in DDL. The dependence of mechanical characteristics of soil on quasistatic nature of dynamic strain in DDL is shown. Conditions to ensure the quasi-static process of strain in soil sample under dynamic compression on DDL are obtained. 10.18720/MCE.85.7 soil dynamic loading waves stresses quasi-statics mechanical characteristics of soil https://engstroy.spbstu.ru/article/2019.85.7/ 07.pdf
RAR RUS 92-106 56826013600 Peter the Great St. Petersburg Polytechnic University Gravit Marina marina.gravit@mail.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
 6508223358 Riga Technical University Serdjuks Dmitrijs Dmitrijs.Serdjuks@rtu.lv
1 Kalku Street, Riga LV-1658, Latvia
 Peter the Great St. Petersburg Polytechnic University Bardin Aleksei kmkbav@gmail.com
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
 LTD «PROMIZOL» Prusakov Vasiliy info@tdpromizol.com Riga Technical University Buka-Vaivade Karina karina.buka.vaivade@gmail.com Fire design methods for structures with timber framework Timber structures are environmentally friendly in terms of decreasing the impact of human activity on the planet. Reliability of timber structures can be provided by the corresponding fire resistance so as fire risk is one of the most significant disadvantages of timber structures. Development of new method for calculation of actual fire resistance is a topical issue. The first draft of method for calculation of actual fire resistance and classes of fire risk for load-bearing timber structures based on Russian national standard, was compared with fire design methods based on European norm. The structure of one-storey glued load-bearing timber framework for sports hall of Corporative University of Sberbank was used as an example for the comparison. The main load bearing structure of the framework in the transversal direction is two-hinge glued laminated timber frame with the span equal to 24 m, consisting of the two columns with rectangular glued cross-sections and trapezium truss with triangular lattice system and two cantilevers. It was stated, that methods based on European norm and method based on Russian national standard enable to obtain comparable results for evaluation of fire resistance for glued laminated load-bearing timber frameworks structure. However, the method based on Russian national standard did not contain information for evaluation of fire resistance of joints of timber structures, which often is determinant for the timber frameworks. Therefore, adding of the chapter including approach to evaluation of fire resistance of the joints of timber structures is possible direction for further development of the method based on Russian national standard. 10.18720/MCE.85.8 glued load-bearing timber framework trapezium timber truss glued timber decking reduced cross-sections method reduced properties method actual fire resistance https://engstroy.spbstu.ru/article/2019.85.8/ 08.pdf
RAR RUS 107-122 57194112309 0000-0001-6184-2365 Vyatka State University Tyukalov Yury yutvgu@mail.ru Calculation method of bending plates with assuming shear deformations The problem of calculating bending plates by the finite element method with considering of shear deformations is considered. The bending plates are widely used as common structures of various objects of civil and industrial construction. The solution was obtained on the basis of the principles of the minimum of additional energy and possible displacements. For approximation of moment fields, piecewise constant functions are used. Shear forces can be approximated by constant or piecewise constant functions. The necessary relations for rectangular and triangular finite elements are obtained. It is shown that the proposed method can be used in combination with traditional finite elements for thin plates obtained by the finite element method in displacements. A comparison of the solutions, obtained by the proposed method, with other known solutions for bending plates, with assuming of shear deformations, is given. A numerical estimate of the accuracy and convergence of the proposed method, when crushing the finite element mesh, is given. 10.18720/MCE.85.9 bending plates shear deformations stresses finite elements https://engstroy.spbstu.ru/article/2019.85.9/ 09.pdf
RAR RUS 123-135 7004452338 0000-0001-8759-6318 National University of Water Environmental Engineering Dvorkin Leonid dvorkin.leonid@gmail.com
Rivne, Ukraine
 Modified water-cement ratio rule for the design of air-entrained concrete Designing concrete compositions, containing entrained air, is usually done by means of empirical proportioning, which is quite a laborious and lengthy process. In the article design formulae are experimentally justified with rule of modified C/W, which is complex due to known empirical dependencies, and allow us to find the content of concrete components with desired strength, frost resistance, and density properties. Conducted experimental studies are: compression method for determining the volume of entrained air as well as standard methods for determining the strength and frost resistance of concrete. Lastly, generated formula was verified on an example for calculating the compositions of heavy concrete with a given strength and frost resistance and structural claydite-concrete with desired strength and density 10.18720/MCE.85.10 modified C/W the volume of air entrained cement consumption strength and frost resistance of concrete pore volume of aggregate composition of lightweight concrete https://engstroy.spbstu.ru/article/2019.85.10/ 10.pdf
RAR RUS 136-145 Amirkabir University of Technology Younesi Adel a.younesi@semnan.ac.ir
Tehran, Iran
 23098221100 0000-0002-4753-7775 Department of Civil Engineering, Semnan University Rezaifar Omid orezayfar@semnan.ac.ir
Semnan, Iran
 0000-0002-9904-8623 Department of Civil Engineering, Semnan University Gholhaki Majid mghlhaki@semnan.ac.ir
Semnan, Iran
 Amirkabir University of Technology Esfandiari Akbar a_Esfandiari@aut.ac.ir
Tehran, Iran
 Structural health monitoring of a concrete-filled tube column Structural Health Monitoring (SHM) has provided an opportunity to assess the reliability and integrity of civil engineering structures. Damage in the structure reduces the hardness and modal properties of the structures. Therefore, changes in dynamic behavior and modal data can be used to identify damage. This study identifies the existence and location of damage in the CFT column based on vibrational analysis techniques. The method for damage detection is based on dynamic analysis on the modal data (mode shape, frequency and damping) of the structure. The experimental results obtained the modal test and the results of the theory of FE simulation have been used to identify the damage. In the first step, after creating the prototype and preparing the test setup, the specimen was subjected to a modal test, so the modal data were extracted, and the Coherence curve test were plotted to confirm the accuracy. Similarly, the FE model is also simulated after validation, so the modal data of the theory were also extracted. In the second step, based on the obtained data, the comparison of frequencies, MAC and COMAC criteria, mode shape and damping of an undamaged and damaged specimens were performed, and the identification of the damage was dealt with. In the third step, the Continuous Wavelet Transform(CWT) tool was used in order to determine the location of the damage in both methods (FE and experimentally), to identify the damage location on the mode shape (CWT input signal). The results show that in the both the methods, the existence of damage in the CFT column is well identified and its location is also determined with high precision, which indicates the ability of damage detection method by CWT techniques. 10.18720/MCE.85.11 CFT column modal data damage identification Structural Health Monitoring CWT https://engstroy.spbstu.ru/article/2019.85.11/ 11.pdf