75504 2712-8172 2 78 2018 1-178

RAR RUS 3-15 Орловский государственный университет Chernyaev Andrey chernyev87@yandex.ru Alternative engineering of steel girder cages by geometrical methods Steel girder cages are widely used as plant buildings ceilings, bridge vaults, locks of hydraulic engineering constructions and other construction objects. An important task in case of their designing is the search of the most economic constructive decision with the smallest amounts of material. Therefore the great value in construction mechanics is attached to the development of methods of search of the most rational and optimal constructive solutions. The new technique of alternative engineering of steel girder cages with various cell forms, i.e. rectangular, triangular, rhombic and other, is offered. The technique is based on the principles of physicomechanical analogies and geometrical methods of construction mechanics. As a research object for a numerical example the girder cage of 12 x 6 m is considered. It has brick walls supporting. Girder profile is made of rolled sections, flooring is steel and solid. The studies showed that using a rhombic cage is the most economic. 10.18720/MCE.78.1 steel girder cages; alternative engineering; geometrical methods; structural mechanics https://engstroy.spbstu.ru/article/2018.78.1/ 01.pdf

RAR RUS 16-29 Semnan University Kafi Mohammad Ali mkafi@semnan.ac.ir Semnan University Kachooee Ali ali.kachooee@semnan.ac.ir The behavior of concentric brace with bounded fuse The concentrically braced system is one of the most common lateral load-bearing systems among the steel structures. This lateral loadbearing system has various apparent forms where the main characteristic of them all is their significant stiffness and lateral strength. The main weakness of the concentrically braced system is buckling in compression. This issue causes that concentric bracings have low compressive load-bearing capacity together with undesirable ductility and limited energy dissipation capacity. In this study to solve this problem use has been made of a heuristic method. In this method a local fuse has been used in the middle of bracing where its periphery and inner circumference have been covered with an auxiliary casing within a casing. The local fuse is designed in a way that after yielding, the bracing undergoes local buckling at this area. But presence of an auxiliary element placed around the fuse prevents this local buckling and thus the bracing would exhibit almost a symmetric behavior during compressive and tensile loadings. Thus the bracing would exhibit a wide and spindleshaped hysteresis curve under a cyclic loading with desirable ductility and high energy dissipation capacity. Also in this article a numerical study is performed utilizing ABAQUS Ver. 6.12 software to make comparison between concentric bracings with local fuse –auxiliary element (LF-AECB) and usual concentric bracings (UCB) in terms of ductility, energy dissipation capacity and loadbearing capacity. The results of numerical studies have indicated the extraordinary better performance of LF-AECB with respect to that of UCB. 10.18720/MCE.78.2 local fuse; concentrically braced structures; ductility; energy dissipation capacity; load bearing capacity; cyclic load https://engstroy.spbstu.ru/article/2018.78.2/ 02.pdf

RAR RUS 30-46 57194431559 0000-0003-4992-2084 Peter the Great Saint Petersburg Polytechnic University Galyamichev Alexander galyamichev@yandex.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Kirikova Victoria vikakirikova@yandex.ru

Polytechnicheskay, 29

57209803918 0000-0002-6056-5498 Peter the Great Saint Petersburg Polytechnic University Gerasimova Ekaterina katyageras17@gmail.com

St. Petersburg, Russia

Riga Technical University Sprince Andina andina.sprince@rtu.lv Bearing capacity of facade systems fixing to sandwich panels The article presents results of the experimental and theoretical research of bearing capacity determination for fixings, used for bearing and supporting brackets in facade systems with the base from sandwich panel. The experiment included the consideration of several types of brackets fixing: using self-tapping screws and threaded rods, taking into account the variation in the thickness of the bearing steel plates. The required values of the research were critical longitudinal force for the pull-out from the base, deformations of the base, which lead to the disruption of sandwich-panel structural integrity. In addition, full-sized samples of the bearing bracket (the most loaded element of the facade system), installed on sandwich panel, were tested for the longitudinal (wind) and shearing (self-weight of cladding and system) load with different types of fixing. As a result, the article gives recommendations for the joints design of facade system brackets fixing to the base from sandwich panel, developed on the results of tests and theoretical studies. 10.18720/MCE.78.3 faсade system; sandwich panel; bracket; screw; facade https://engstroy.spbstu.ru/article/2018.78.3/ 03.pdf

RAR RUS 47-64 Moscow State University of Civil Engineering Tusnin Alexandr valeksol@mail.ru

Moscow, Russia

Dynamic factors in case of damaging continuous beam supports The article provides the research results of the continuous beam operation in case of the support damage. When the support is damaged, the design model of the beam is changing, the spans are increasing, and the force in the beam is increasing. Moreover, a fast removal of the support at the effect of the unaltering during the destruction of the beam concentrated or distributed force will lead to the evolvement of the vibrations and increase of the beam force. The theoretical jurisdictions are provided for the determination of dynamic factors which might be used for the determination of dynamic force based on the results of the static calculations for the damaged construction. Theoretical dynamic factors are determined for the beams loaded by the concentrated loads. The numerical computations have been performed with the use of finite-element design models. By the example of the continuous beams loaded by the concentrated and distributed forces, the consequence of the dynamic calculations for damaged beams is shown taking to account the time of the support breakdown. It is set that the maximum force values appear in the beams with time for the support damage from 0.01 to 0.1 sec. The comparison of theoretical and numerical dynamic factors is conducted. It showed a good compliance of factor values determined by different methods. The recommendations are provided for practical applications of the dynamic factor at the calculation of continuous beams. 10.18720/MCE.78.4 beam; support; liveness calculations; dynamic factor; dynamic calculations; frequency; time length https://engstroy.spbstu.ru/article/2018.78.4/ 04.pdf

RAR RUS 65-75 15730895100 http://orcid.org/0000-0003-3251-3356 Saint Petersburg State University of Industrial Technologies and Design Gorshkov Alexander alsgor@yandex.ru

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

Military Space Academy named after A.F. Mozhaysky Rymkevich Pavel rymkewitch@yandex.ru RUE "STROYTEHNORM" Kydrevich Olga kudrevich@stn.by Payback period of investments in energy saving Authors developed a mathematical model for estimating the discounted payback period of investments for reducing energy resources needed in building's development. Obtained equations allow calculating the projected payback period for investments in energy saving, taking into account the size of the investment, the estimated or actual value of the achieved energy saving effect, the dynamics of energy carriers tariff growth, the discounting of future cash flows, and also a value and a period of loan repayment. The proposed mathematical model allows to perform quickly and efficiently a comparison of various energy-saving solutions based on economic viability and choose the most optimal from them. 10.18720/MCE.78.5 civil engineering; buildings; energy resources; energy consumption; operating costs; investments; return of investments; payback period; energy efficiency; energy saving https://engstroy.spbstu.ru/article/2018.78.5/ 05.pdf

RAR RUS 76-90 National Research Moscow State Civil Engineering University Zuikov Andrey zuykov54@mail.ru “SKB – Engineering” Ltd Bakunjaeva Viktorija vbakunyaeva@yandex.ru Moscow State Automobile and Road Technical University Artemyeva Tatiana ArtemyevaTV@yandex.ru Moscow State Automobile and Road Technical University Zhazha Elena l-jaja@mail.ru Flow states in the classical Venturi channel water gauge The paper relates to the field of hydraulics and is devoted to the study of fluid flow states in a non-submerged Venturi channel. The aim is improvement of the method of hydraulic calculation of the classical Venturi channel. Authors applied experimental methods with the use of hi-tech certified measurement equipment allowing for digital technology-based automated collection and processing of empirical information; calculation and analytical methods. Distribution of depths, velocities and Froude numbers in flow direction inside the classical Venturi channel water gauge are obtained. The theoretical method of hydraulic calculation of the full-capacity discharge of the Venturi channel is considered, which does not contain empirical coefficients. It is established that the calculation of the full-capacity discharge of the classical Venturi channel in accordance with the current State Standard of the Russian Federation MI 2406-97 gives underestimated values of the design flow rate with the actual flow rate with a systematic error of more than -2 %, the theoretical method of hydraulic calculation of the full-capacity discharge of the Venturi channel has a relative error of ±1 %. 10.18720/MCE.78.6 open channel flow; liquid flow rate measurement; Venturi flume; critical depth https://engstroy.spbstu.ru/article/2018.78.6/ 06.pdf

RAR RUS 91-100 Moscow State Civil Engineering University (National Research University) Obukhova (Shekhovtsova) Svetlana SHehovtsovaSYU@mgsu.ru

Moscow, Russia

LLC GAZPROMNEFT - BITUMEN MATERIALS Korotkov Aleksey Korotkov.AV@gazprom-neft.ru V.G. Shukhov Belgorod State Technological University Vysotskaya Marina roruri@rambler.ru Method of forecasting the effectiveness of cationic bitumen emulsions Approbation of the procedure for predicting the production of effective bitumen emulsions at the stage of water phase preparation and also predicting the compatibility of the mineral aggregate and the surface-active substance used to emulsify the bitumen was carried out. As criteria characterizing the optimal composition of water phases, the following indicators were proposed: the surface tension of the water solutions under investigation and the wetting contact angle. The study of the dynamics of changes in the properties of the water phase and surface tension at the interface of the "water phase–mineral substrate" system during the emulsifier concentration change made it possible to establish that in the range of the emulsifier content for the bitumen emulsion recommended by the manufacturer, there are ineffective concentrations, the effect and variability of which is manifested in case of contact with mineral materials of different nature. The possibility of early prediction of the compatibility of the emulsifier used to prepare the bitumen emulsion and the mineral material, which will interact with the production emulsified binder, was evaluated. 10.18720/MCE.78.7 bitumen emulsion; emulsifier; surface-active substances; surface tension; interfaces https://engstroy.spbstu.ru/article/2018.78.7/ 07.pdf

RAR RUS 101-115 Donbas National Academy of Civil Engineering and Architecture Mushchanov Volodymyr volodymyr.mushchanov@mail.ru Donbas National Academy of Civil Engineering and Architecture Orzhekhovskii Anatoly aorzhehovskiy@bk.ru Donbas National Academy of Civil Engineering and Architecture Zubenko Hanna zubienko_anna@mail.ru Donbas National Academy of Civil Engineering and Architecture Fomenko Serafim fomenko_sa@mail.ru Refined methods for calculating and designing engineering structures The enhancement of calculation of different structures for engineering constructions which is carried out on the main stages of design, has been considered in this paper: 1) the formation of loads (for structures of vertical cylindrical tanks); 2) improving the design solutions (for structures of rigid bus); 3) assessing the reliability of the adopted design decisions by probabilistic and statistical methods (on the example of frame-cantilever coatings above the stands of stadiums). The main aim of the research carried out in solving the first problem is to improve the method for normalizing the wind load on the surface of a cylindrical tank with a volume of 20000–50000 m3 , taking into account the type of roof (sagging membrane) and the block arrangement (a group of 4 tanks). The solution of the second problem has been considered on the example of new damping devices to reduce oscillations generated by the wind flow of the rigid jumper construction of girder type. The normative documents formulate only general requirements, but at the same time, there are no specific recommendations on rational sizing of oscillation dampeners and data on their application efficiency. The the third problem has been solved on the example of reliability estimation of design project solutions of frame-consol cover structures over stadium tribunes, taking into account the casual character of the main design factors. 10.18720/MCE.78.8 vertical cylindrical tank; rigid bus; frame-cantilever coating; design; calculating https://engstroy.spbstu.ru/article/2018.78.8/ 08.pdf

RAR RUS 116-127 Ural Federal University named after first president of Russia B.N. Yeltsin Vedishcheva Iuliia j.s.vedishcheva@urfu.ru Ural Federal University named after first president of Russia B.N. Yeltsin Ananin Michail m.y.ananin@urfu.ru Technical University in Košice Al Ali Mohamad mohamad.alali@tuke.sk M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru

Polytechnicheskay, 29

Influence of heat conducting inclusions on reliability of the system “sandwich panel – metal frame” The paper presents results of numerical research oriented to the influence of heat conducting inclusions on thermo-technical properties of vertical and horizontal sandwich panels. Sandwich panels consist of flat steel sheets and thermal insulation core (from foam polystyrene, foam polyurethane and rock wool). Thread forming screws, which cross the sandwich panel through its depth, and connect the sandwich panel to frame, creates the heat conducting inclusions. The numerical analysis is carried out using software ANSYS. Based on the numerical analysis results, the regression equations for calculation of minimal values of temperature on an internal surface of a vertical sandwich panel are easy to obtain. The analysis of thermal field of the “sandwich panel – metal frame” system shown that the hygiene requirements are not complied. Proposed solution allows the reduction of the influence of heat conducting inclusions on thermo-technical properties. 10.18720/MCE.78.9 sandwich panel; temperature field; energy efficiently; thermal bridges; enclosing structures; throat forming screws; heat conduction inclusions https://engstroy.spbstu.ru/article/2018.78.9/ 09.pdf

RAR RUS 128-135 Peter the Great Saint Petersburg Polytechnic University Struchkova Ayyyna ayyyna_struchkova93@mail.ru

Polytechnicheskay, 29

7801686579 0000-0001-7011-8213 Peter the Great Saint Petersburg Polytechnic University Barabanschikov Yuri ugb@mail.ru

Polytechnicheskay, 29

Peter the Great St. Petersburg Polytechnic University Semenov Kirill kvsemenov@bk.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great Saint Petersburg Polytechnic University Shaibakova Albina albinashaibakova@gmail.com

Polytechnicheskay, 29

Heat dissipation of cement and calculation of crack resistance of concrete massifs In this paper, the problems of thermal cracking resistance of massive concrete and reinforced concrete structures during the building period are considered. The calculation results of a research on the effect of hardening temperature on the process of heat dissipation process of concrete are given. The analysis of the thermal stressed state of a massive foundation plate with a fixed thickness of thermal insulation was carried out, the values of the minimum thicknesses of the surface thermal insulation ensuring cracking resistance of structure were obtained. Calculations are performed at various plate heights taking into account the effect of hardening temperature on heat dissipation and without this account. The conducted research demonstrates that not taking into account the effect of hardening temperature on the process of heat dissipation in problems of ensuring cracking resistance of concrete and reinforced concrete massifs leads to a noticeable increase in the required thickness of the necessary thermal insulation. 10.18720/MCE.78.10 thermal stressed state; thermal cracking resistance; massive concrete and reinforced concrete structures; hydration of cement; building period https://engstroy.spbstu.ru/article/2018.78.10/ 10.pdf

RAR RUS 136-150 Peter the Great Saint Petersburg Polytechnic University Bespalov Vladimir chanchullero@yandex.ru

Polytechnicheskay, 29

Middle East Technical University Ucer Deniz deucer@metu.edu.tr Peter the Great Saint Petersburg Polytechnic University Salmanov Ildus ildussalmanov@gmail.com

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Kurbanov Israfil Israfil-kurbanov@mail.ru

Polytechnicheskay, 29

Saint-Petersburg Mining University Kupavykh Svetlana Siniavina_SV@pers.spmi.ru

2, line 21 V.O., St. Petersburg, 199106, Russia

Deformation compatibility of masonry and composite materials Fiber Reinforced Polymers (FRP) are commonly used nowadays for strengthening deteriorated structures. The purpose of this research was to determine the combined behavior of masonry walls and reinforcing meshes together, according to their deformation characteristics. A sample wall with average masonry parameters and seven different common polymer nets on them were modeled in Abaqus Software. Moreover, a case study wall was also modeled according to the strength values obtained from direct testing of a demolished masonry wall that was shaped as secondary blocks for reusing purposes. In addition to the analysis of this plain recovered wall, the strengthened version of it with carbon fiber polymer mesh was also modeled. The results obtained from the theoretical sample wall and the case study wall with plain and reinforced alternatives stated that; the compatibility of deformation characteristics between the wall and the reinforcing mesh is the key for combined strength behavior of the wall. Lastly, besides illustrating and discussing all the stress-strain conditions for the analyzed cases, this study also offered a formula for the detection of combined behavior in question, according to the material properties of unreinforced wall and reinforcing mesh separately. This formula is quite useful in order to decide to the suitable mesh type prior to the application. 10.18720/MCE.78.11 masonry FRP simulation deformation compatibility composite materials compression-bending element https://engstroy.spbstu.ru/article/2018.78.11/ 11.pdf

RAR RUS 151-160 Peter the Great Saint Petersburg Polytechnic University Rassokhin Aleksandr rassokhinaleksandr@gmail.com

Polytechnicheskay, 29

Ponomarev Andrey 9293522@gmail.com International Nanotechnology Research Center Polymate Figovsky Oleg figovsky@gmail.com

Migdal Haemek, Israel

Silica fumes of different types for high-performance fine-grained concrete One of the most often and successfully applied admix as a part of the modified concrete is active amorphous silica fume. The increased practical interest in this admix has led to emergence in the market of various producers and also to emergence of different types (brands) of the silica fume produced from various raw materials with use of various technologies. At the same time their makeup, dispersion and content of silicone dioxide drastically ranges. It takes toll on results of use of such admixes in relation to the same recipes of concrete mixtures. The research is focused on the experimental study of the most useful types of active silica fume and the comparison of results of their using in fine-grained concrete. Results of these researches have shown a dependence of properties of the modified concrete on the content of active silica fume and from degree of its dispersion. The best results had silica fumes produced as the accompanying product by silicon production and including some additional quantity of particles of nanodimensional carbon. 10.18720/MCE.78.12 silica fume; fine grained concrete; modified concrete; nanocarbon; comparation of properties https://engstroy.spbstu.ru/article/2018.78.12/ 12.pdf

RAR RUS 161-168 0000-0003-2533-9732 National Research Moscow State Civil Engineering University Samarin Oleg samarin-oleg@mail.ru The temperature waves motion in hollow thick-walled cylinder 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 article it deals with the study of propagation of temperature waves in the wall of the hollow cylinder after a sudden temperature change of the internal environment, fuss-causes upon termination of the movement or circulation of the heated stream. 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 of the penetration depth of the temperature wave according to the considered algorithm, depending on the time since the start of heat exposure and their comparison with the existing data for one-dimensional case are given for the implementation of the identification obtained mathematical model. Calculated radial profiles of relative temperature in the cylinder wall within the temperature waves in dimensionless coordinates and the analytical approximation relations for the description of these profiles are presented. The results are compared with the existing analytical solution for an unlimited array in rectangular coordinates and it is marked that 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 minimum temperature 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.78.13 hollow cylinder; thermal conductivity equation; finite-difference scheme; temperature wave; temperature profile; cylindrical symmetry https://engstroy.spbstu.ru/article/2018.78.13/ 13.pdf

RAR RUS 169-178 AAC-8977-2019 36771895000 StaDyO Research & Engineering Centre Belostotsky Alexander amb@stadyo.ru

Moscow, Russia

StaDyO Research & Engineering Centre Akimov Pavel pavel.akimov@gmail.com National Research Moscow State Civil Engineering University Negrozov Oleg genromgsu@gmail.com National Research Moscow State Civil Engineering University Petryashev Nikolay stadyo@stadyo.ru National Research Moscow State Civil Engineering University Petryashev Sergey petsero@mail.ru National Research Moscow State Civil Engineering University Sherbina Sergey serg_msk89@mail.ru OOO "Pixar" Kalichava Dmitry 2109962@gmail.com Russian Academy of Architecture and Construction Sciences Kaytukov Taymuraz tkaytukov@gmail.com Adaptive finite-element models in structural health monitoring systems The design and construction of unique buildings, facilities and complexes of “modern” architectural forms and constructive solutions in Russia began less than 20 years ago in the conditions of a shortage of national design codes and experience of such construction. Thus these objects were not provided with proper scientific and technical support and structural health monitoring (SHM) systems. Generally only the instrumental monitoring system, based on results of finite element analysis and comparison with measured data allows performing planning activities to prepare for and respond to changes in state of critical structures and drawing conclusions about the actual state and the possibility of further safe operation of the building. Theoretical foundations of methodology of such SHM have been developed. Parameterized finite element models of buildings, special algorithm of adaptation (calibration) in accordance with results of measurements, methodology of measurements of natural frequencies and modal shapes and algorithm of structural evaluation are proposed in this paper. So-called “start” finite element model is normally developed to study the load-bearing capacity of the current version of the project. Parameterized “monitoring-oriented” three-dimensional dynamic finite element model for each significant stage of life cycle of the building (the stages of construction and operation) is constructed or modified, verified and adapted in accordance with the measured data. The main criterion for the adaptation is the correspondence of calculated and measured spectrum of the natural frequencies and mode shapes in the entire frequency range, significant for the assessment of system-wide changes and for identification – localization of possible defects. 10.18720/MCE.78.14 structural health monitoring; finite element method; adaptive models; unique buildings; seismometric approach; standing wave method; natural frequencies https://engstroy.spbstu.ru/article/2018.78.14/ 14.pdf