33407 2304-6295 Construction of Unique Buildings and Structures 6 91 2020 1-105
RAR RUS 9101-9101 57189359179 0000-0002-1030-8370 Peter the Great St. Petersburg Polytechnic University Tarasov Vladimir Aleksandrovich vtarasov1000@yandex.ru
St. Petersburg, Russian Federation
 Double Seismic Insulation System of Turbine Unit Foundation Seismic isolation is the most effective way to achieve earthquake resistance of equipment located inside buildings and structures. Achievement of seismic stability power plant turbine foundation by applying a variety of design solutions and seismic isolation systems is a significant issue. The Earth population growth and as a result, an increase in the required electric capacities are the main causes to design and build more facilities of increased responsibility (such as power plants) in areas with high-level seismic actions. Improving the reliability and safety in the design of power plants is achieved by the resistance of buildings, structures, and equipment to special types of external influences, including seismic. Ensuring the seismic resistance of building structures and technological equipment is one of the key tasks in the design of power plants in seismically active territories. A new constructive solution of the turbine building is proposed: the turbine building, which contains the turbine unit foundation, which is vibration-insulated with spring and spring-damper blocks, is completely isolated by introducing a layer of seismic isolators under the foundation plate of the building. The turbine unit foundation is twice isolated. Plenty of calculation experiments using the FEM were carried out. Three different structural schemes of the turbine unit foundation as part of the turbine building are analyzed: foundation without seismic isolation; classic vibration-insulated foundation (foundation with a standard seismic isolation system); foundation with double seismic isolation system. The dynamic behavior of the foundation with a double seismic isolation system is also analyzed at a different vertical stiffness ratio and horizontal stiffness ratio of the “bottom” layer seismic isolators. The greatest decrease in horizontal seismic accelerations in the axial direction at the turbine installation level achieves when the double seismic isolation system with slider seismic supports in the lower layer is used. 10.18720/CUBS.91.1 69 Seismic isolation Seismic insulation system Response spectrum Seismic stability Turbine unit foundation Earthquake Structural dynamics Seismic calculation https://unistroy.spbstu.ru/article/2020.91.1/ 9101.pdf
RAR RUS 9102-9102 57197871018 0000-0001-7284-7209 RUDN University Ucer Erduran Deniz denizucer.arch@gmail.com
Moscow, Russian Federation
 Precast Block Houses Built in the 1950s and Urban Mining Potential The transformation of the urban environment in Moscow continues at a high pace with the new constructions, renovations, and demolitions. Identical mass housing blocks built in the 1950s and after, which are also prevalent over Europe, are of distinct importance in this transformation since they generate a precious resource of industrialized precast concrete components. A nine-story precast dwelling type of the specified period is the research material in this current study for the determination of present material stock and its usability. Original design booklets and guidelines published by the planning committees in the 1960s and 70s provided architectural design-related data -i.e., materials, dimensions, and assembly details. Moreover, the visual investigation of facade components on ten randomly selected buildings revealed their current state. Design data invariably showed that constructors typically gathered these precast components using steel anchors and cement, which naturally evokes the critical question for their possible separation and reuse. Additionally, the visual survey sufficiently illustrated that the surface quality of these components was high, which is a valuable hint for their further utilization. According to our simple calculations, the selected building type comprises 915 precast facade components, which results in 778 thousand for the entire series in Moscow. In brief, the possible recovery of this tremendous amount from the landfill or downcycling is crucial in terms of environmental welfare, as the components of other identical buildings in the city and the country. Owing to the presence of similar structures all over Europe, this verdict is also valid and useful for different contexts. Consequently, the precast components used during the 1950s over many countries are still re-usable and their separation from the demolition waste creates a significant environmental impact reduction. 10.18720/CUBS.91.2 69 Urban mining Industrialized housing Precast concrete Reuse Russia https://unistroy.spbstu.ru/article/2020.91.2/ 9102.pdf
RAR RUS 9103-9103 56200412900 0000-0002-5851-152X Nosov Magnitogorsk State Technical University Krishan Anatoly Leonidovich al.krishan@magtu.ru
Magnitogorsk, Russian Federation
 55967058400 0000-0001-5086-5713 Nosov Magnitogorsk State Technical University Chernyshova Elvira Petrovna ep.chernyshova@gmail.com
Magnitogorsk, Russian Federation
 Nosov Magnitogorsk State Technical University Likhidko Mikhail Alekseevich likhidkom@yandex.ru
Magnitogorsk, Russian Federation
 Nosov Magnitogorsk State Technical University Zakieva Louisa Rishatovna
Magnitogorsk, Russian Federation
 Mechanical Properties of Compressed Concrete with Confinement Mesh Reinforcement The study objects are compressed reinforced concrete structures with confinement mesh reinforcement. The purpose of the work is to determine the dependencies that allow the most reliable calculation of the coordinates of the vertices of a curvilinear state diagram of volumetric compressed concrete of such structures. An analysis of the known formulas for determining the strength of volumetric compressed concrete is performed. According to the results of an analytical assessment of the influence of lateral pressure from the deterrent effect of confinement reinforcement on concrete strength, the corresponding formula is proposed. It takes into account the existing unevenness of the lateral compression of the concrete core. Based on the phenomenological approach, a formula for determining the deformation at the vertex of the deformation diagram of volumetric compressed concrete is obtained. The analysis shows, that the proposed formulas represent the main factors affecting the strength and ultimate strain of concrete with confinement mesh reinforcement. Using these formulas, the main indicators of the statistical analysis of the results of the comparison of the theoretical date with the experimental results are much better than when calculated according to other known dependencies. 10.18720/CUBS.91.3 69 Compressed elements Confinement reinforcement Volume compression Strength Ultimate deformation https://unistroy.spbstu.ru/article/2020.91.3/ 9103(1).pdf
RAR RUS 9104-9104 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru
Moscow, Russian Federation
 The Stress-Strain State of a Rectangular Covering Spatial Truss The object of research is a model of a statically definable roof truss with supports on the sides of the structure. Spherical and cylindrical supports are located at two corner points of the covering, in other corners and on the sides of the structure at an equal distance from each other — stands. A multi-dome surface shape is set. For the case of loading the truss by the force in the middle of the span by the induction method according to the number of panels, the formula for the deflection is derived. Analytical dependencies of the reactions of supports on the number of panels under the action of a load uniformly distributed over the nodes of the coating surface are found. Method. The calculation of the forces in the rods and the reactions of the supports of an externally statically indeterminate truss is performed in symbolic form using the method of cutting nodes. To compose a system of equilibrium equations and obtain a solution, the operators of the Maple computer mathematics system are used. The deflection is determined by the Maxwell-Mohr's formula. Based on the data on the solution of a series of trusses with a sequentially increasing number of panels by the induction method, formulas for the dependence of the deflection on the load, the size and number of panels of the structure are derived. Operators of the genfunc software package from the Maple computer mathematics system are used to compose and solve homogeneous linear recurrent equations, which are satisfied by the sequences of the coefficients of the sought dependencies. Results. Dependences of deflection and forces on the number of panels have a form polynomial in the number of panels. It is shown that the vertical reactions of the corner supports can have negative signs, which makes it necessary to use retaining supports here. The curves illustrating the solution have a clearly pronounced jump-like shape. The quadratic asymptotics of the solution is found both in terms of the number of panels and linear in height. The dependence of the deflection on the height has a theoretically permissible minimum. The considered scheme of a spatial statically definable roof truss allows an analytical solution to the deflection problem. The obtained dependences can be used to estimate the accuracy of numerical solutions and in problems of optimization of the structure in terms of rigidity and solutions. 10.18720/CUBS.91.4 69 Spatial truss Covering Deflection Induction Maple Analytical solution Asymptotics Holding supports https://unistroy.spbstu.ru/article/2020.91.4/ 9104(1).pdf
RAR RUS 9105-9105 57191527012 0000-0002-2880-3302 V.I. Vernadsky Crimean Federal University Shalenny Vasiliy Timofeevich v_shalennyj@mail.ru
Simferopol, Russian Federation
 Resource saving pile columns and slabs in top-down technology The solutions for resource-saving technology for the construction of pile columns and reinforced concrete floors of multi-story underground structures using the well - known «top-down» method has discussed. The observed disadvantages and ways to improve the design of the pile-column to facilitate the cleaning of its upper, column part are shown. For this purpose, it is proposed to mount a removable polymer shell on the pipe-formwork, mainly in the form of a pipe made of vinyl plastic, which practically does not have adhesion to the concrete mixture during its hardening. Further improvement of the organizational and technological scheme for the construction of monolithic reinforced concrete structures of the multi-story underground part of civil facilities using the «top-down» method consists of setting and solving the problem of installing several floors in a single assembled formwork. The problem is solved by the proposal to move the specified formwork without disassembly from the top to the next level below the projected level. A simulation of the technology and organization of work on a specific civil building with a developed multi-story underground part - Parking. As a result of the comparative efficiency assessment, the cost of constructing an underground multi-story Parking lot using improved technology was reduced by 3.4% and the total duration of work was reduced by 3.6%. This did not take into account the economic effect associated with reducing the construction time of the object. 10.18720/CUBS.91.5 69 top-down technology pipe-columns adhesion underground floors reinforced concrete flooring formwork resource saving technical and economic indicators https://unistroy.spbstu.ru/article/2020.91.5/ 9105.pdf
RAR RUS 9106-9106 6506150284 0000-0003-1139-3164 Moscow State University of Civil Engineering Sainov Mikhail Petrovich mp_sainov@mail.ru
Moscow, Russian Federation
 0000-0001-9723-5161 Le Quy Don Technical University Nguyen Trong Chuc ntchuc.mta198@gmail.com
Hanoi, Viet Nam
 Temperature Regime of Rockfill Dam Concrete Face During the Filling of the Reservoir Introduction. Recently the issue of study in thermo-stressed state of rockfill dam concrete faces has become urgent. This is related to the fact that stresses from thermal effects may be one of the reasons that cause crack formation in a concrete face. This paper investigates the character of a thermal effect to which the face is subject during the reservoir impoundment. Materials and methods. There was studied nonstationary temperature regime of a fragment of a dam structure with a concrete face at the contact with cold water. Two cases were considered: rapid reservoir impoundment and impoundment with water rise rate 1 m a day. The study was conducted by numerical modeling method with the aid of the commercial software system ANSYS and the authorial computer program. It was shown that in order to obtain adequate results, the finite-element model should be in great detail. Results. Analysis showed that after the reservoir impoundment the face temperature regime is installed a durably, about one month. At a rate of 1m/day reservoir water level rise the face temperature regime is formed during a longer time than at rapid reservoir impoundment. The face temperature regime varies more intensively during the first three days. During this time interval, the face is subject to a high temperature gradient. Conclusion. The face temperature regime at the reservoir water level variation, characterized by a high temperature gradient during several days, evidences about unfavorable thermal effect, because it results in the face bending deformations. At stress-strain state analyses of a concrete face, it is reasonable to consider the thermal effect characterized by the temperature variation not throughout the whole thickness of the face but only in the part nearest to the upstream face. 10.18720/CUBS.91.6 69 Concrete faced rockfill dam temperature regime reservoir filling thermo-stressed state temperature gradient https://unistroy.spbstu.ru/article/2020.91.6/ 9106.pdf
RAR RUS 9107-9107 0000-0003-3579-6654 Moscow State University of Civil Engineering Dvornikov Ruslan Mikhailovich ruslan_dvornikov94@mail.ru
Moscow, Russian Federation
 6602103175 0000-0002-6742-8621 Moscow State University of Civil Engineering Velichko Evgenii Georgievich pct44@yandex.ru
Moscow, Russian Federation
 Wood Concrete Modified with Ground Granulated Blast Furnace Slag Increasing requirements for the physical and mechanical properties of building materials give impetus to the creation and improvement of new high-performance building materials, which include slag-silicate wood chip concrete. The object of research is high-performance wood chip concrete materials obtained using modified slag-silicate binders. On the first stage of the work, the physical and mechanical properties of fine-dispersed granulated blast furnace slag and wood chips were studied. Methods: The phase composition of the fine-dispersed granulated blast furnace slag was determined by x-ray phase analysis. Also, the microstructure of the sample of the ground granulated blast furnace slag was studied using electron microscopic analysis. Results: It was founded that that slag consists of a crystalline and amorphous phase. The content of its most active amorphous phase is on the level of 59.8%. The chemical composition for the ground slag sample was also done. As a result of that, the element composition of the ground slag was obtained. In particular, the slag basicity factor which value equals to 1.04, was defined. During the experiment, it was found that the slag mainly consists of large thickened irregular-shaped particles and their aggregates which diameters are from fractions of microns to several microns. At the same time, finer particles are subject to aggregation. On the second stage of the study, three experimental composition of slag-silicate wood chip concrete with different grouting fluid/slag ratio was developed. A water glass solution with a density equal to 1.31 g/cm3 was used as a grouting fluid. As a result of the study, the composite material with an average density of 730 kg/m3, and the strength in 1.92 MPa was obtained. The dependence of the strength changing of slags-silicate wood chip concrete on the ratio of the grouting fluid/binder and the functional relationship of its strength and density were determinate. Based on the results of the experiments, it was founded that the optimal physical and mechanical properties of the slag-silicate wood chip concrete are achieved for the composition with the grouting fluid slag ratio equal to 0.52. 10.18720/CUBS.91.7 69 Alkali-activated materials composite material ground granulated blast furnace slag water glass wood chip concrete strength properties https://unistroy.spbstu.ru/article/2020.91.7/ 9107.pdf
RAR RUS 9108-9108 ABD-2048-2021 57205074229 0000-0003-3154-8207 Peter the Great St. Petersburg Polytechnic University Sabri Mohanad Muayad Sabri mohanad.m.sabri@gmail.com
St. Petersburg, Russian Federation
 6507787139 “Georeconstruction” Institute Shashkin Konstantin Georgievich
St. Petersburg, Russian Federation
 Subsoil Stabilized by Polyurethane Resin Injection: FEM Calculation The soil injection technology using an expandable polyurethane resin is one of the most efficient modern techniques that have been actively used in recent years for soil stabilization and foundations lifting. There are many advantages of using this technology, such as the rapid and strictly controlled process of lifting foundations, ease of use, high mobility and the lightweight of injectable foaming resin in addition to the independence of the physical and mechanical properties of resin from groundwater level, which allow the application of the proposed technology in a variety of geotechnical conditions and projects of various specificities. As part of the study of this technology in the world, very few theoretical and practical studies have been conducted. Most of these studies are focused mainly on the process of raising the foundations and monitoring of this technology. Thus, various monitoring methods have been developed around the world to control the injection process and to provide adequate tracking and a sufficient degree of visualization of the foundations lifting process in various geotechnical situations. Nevertheless, the application of this technology in the field of the soil stabilization and foundation strengthening has so far had certain limitations due to the lack of sufficient scientific theoretical and experimental justifications for the combined behavior of the composite (soil-resin) and the absence of an advanced calculation method, that allows predicting the altered characteristics of the treated soil massive after its injection by the expandable resin.  The article demonstrates the results of a developed calculation method for predicting the averaged characteristics of the strengthened massive of a soil base after its injection by an expandable resin, based on theoretical and practical evidence obtained as a result of field and laboratory experiments, utilizing different approaches of the finite element method. The obtained by the developed calculation method results have been compared to the results of in-situ plate load tests obtained from field experiments without the injection of the resin and after its inclusion into the massive of the investigated soil to verify its accuracy. 10.18720/CUBS.91.8 69 soil injection technology expandable polyurethane resin foundation lifting strengthening plate load test triaxial test finite element analysis calculation method bearing capacity settlment https://unistroy.spbstu.ru/article/2020.91.8/ 9108.pdf