33407 2304-6295 Construction of Unique Buildings and Structures 7 92 2020 1-105
RAR RUS 9201-9201 56297902900 0000-0003-2842-4633 OZIS-Venture LLC Ulybin Alexey Vladimirovich ulybin@mail.ru
St. Petersburg, Russian Federation
 0000-0001-9669-5262 Technotest LLC Kharitonov Aleksandr Yurevich
Moscow, Russian Federation
Low Strain Integrity Testing of Piles. Application for Piles Located under Pile Cap Pile diagnostics, namely the control of integrity and length, is a very urgent task both during the construction of buildings and structures and during their inspection. Regular conditions for control are the availability of free access to the pile head. However, in many cases, the task is complicated by the presence of a cap on piles. This significantly complicates not only the technology for measuring by Pulse Echo Method and the Transient Response Method, but also the process of received signal processing. The data obtained by numerical modeling and field tests in the “pile cap, pile, ground” system are presented in the article. It is shown that the waves transmitted across the boundary between a pile cap and pile are sequential and not in the form of a single pulse. If there are two or more piles in the “pile cap–pile–ground” system the signal response above the test pile will be “noisy” by reflections from neighboring piles. The possible options for performing measurements in case of lack of access to the pile head (the presence of a pile cap) are described in detail. Information about the location of the sensor and striking to wave generation is given. The construction of the new sensor which allows to measure on the side surface of the pile without creating a horizontal platform on the pile is briefly described. Examples of various objects with studied piles united by a cap are given. The investigated objects have a pile caps of various designs: continuous footing, pad, and slab foundation. On the graphics obtained as a result of measurement reflections from the pile toe are clearly identified. It has been practically shown that by using the method of filtering and comparing signals response on the test pile it is possible to control the length of piles located under the pile cap of various types and construction. 10.18720/CUBS.92.1 69 Pile control Pile length Pile integrity Pile cap Grillage Raft Pulse echo method Low strain tes Pile integrity test Foundation survey https://unistroy.spbstu.ru/article/2020.92.1/ 9201.pdf
RAR RUS 9202-9202 12039592100 0000-0003-4283-0400 South Ural State University Korolev Aleksandr Sergeevich korolev@sc74.ru
Chelyabinsk, Russian Federation
 57194202492 South Ural State University Zyrianov Fedor Aleksandrovich zyrianovfa@susu.ru
Chelyabinsk, Russian Federation
 Layer model of the cement composites deformation in the reinforced masonry structures The object of the study is unreinforced and reinforced masonry made of ceramic block. The deformative properties of the object under a compressive load are studied. The elastic modulus' actual and calculated parameters were determined according to standard calculation methods and the proposed layer model. Based on the analysis of the obtained data, the layer calculation model's suitability is revealed, and an advanced method for predicting the elastic modulus of reinforced masonry, including using fiberglass reinforcement, is proposed. A prospective study of the suitability of the layer model for use in composite structures is performed.  10.18720/CUBS.92.2 69 Modulus of elasticity of concrete Deformability of concrete Relative elastic deformations Relative residual deformations Layered calculation model https://unistroy.spbstu.ru/article/2020.92.2/ 9202(1).pdf
RAR RUS 9203-9203 57205072984 0000-0002-5527-0345 Peter the Great St. Petersburg Polytechnic University Mohireva Arina Olegovna mohirevaarina@mail.ru
St. Petersburg, Russian Federation
 57216910533 0000-0001-9935-9205 Riga Technical University Proskurovskis Arturs arprosk@gmail.com
Riga, Latvia
 57205073417 https://orcid.org/0000-0002-1522-0618 Peter the Great St. Petersburg Polytechnic University Glebova Ekaterina Alekseevna glebova_katerina_glk@mail.ru
St. Petersburg, Russian Federation
 57216911232 0000-0001-6383-6639 Peter the Great St. Petersburg Polytechnic University Nazinyan Levon Gaikovic nazinyan.lg@edu.spbstu.ru
St. Petersburg, Russian Federation
 57216911265 0000-0003-3484-6832 Peter the Great St. Petersburg Polytechnic University Belousov Nikita Dmitrievich
St. Petersburg, Russian Federation
 Strength and deformability of compressed-bent masonry structures during and after fire Monitoring of structures in conditions of beyond design basis impacts, including fire and similar impacts associated with exposure to elevated temperatures, which is relevant for both civil and industrial buildings, is especially important. The least studied area is the behavior of compressed-bent masonry structures in such conditions. Based on experimental data, a numerical analysis of compressed-bent masonry structures was carried out. Elevated temperatures from 500 to 1200 degrees were taken. Moreover, we took into account the change in the deformation-strength properties of the masonry depending on temperature, as well as the uneven heating of the structures and the stage of their cooling. The analysis results showed that at the stage of heating and maintaining a high temperature, the behavior of structure changes slightly, with the exception of temperatures of 1000-1200 degrees, when the material becomes ultra-brittle. It was also revealed that the most dangerous stage of cooling at the initial temperature rise above 800 degrees. This circumstance can be taken into account when developing monitoring systems for industrial facilities. 10.18720/CUBS.92.3 69 Elevated temperature Masonry Compress-bent structures Fire resistance Numerical models https://unistroy.spbstu.ru/article/2020.92.3/ 9203-(1)_edited.pdf
RAR RUS 9204-9204 0000-0002-5220-1264 Moscow Power Engineering Institute Vorobev Oleg Vladimirovich olvarg@mail.ru
Moscow, Russian Federation
 Bilateral Analytical Estimation of the First Frequency of a Plane Truss The object of research is the statically determinate cantilever truss. The trass consists of rectangular panels with downward diagonal beams. The truss has two supports, one of which is fixed hinged, and another one is roller support. Masses are located in the nodes of top and bottom chords. Forces in the bars and reactions at supports are determined using the method of joint isolation. The vertical displacement of nodes is derived from the Maxwell-Mohr method with the premise of linear elasticity. Dependence of vertical displacement, Dunkerley’s and Rayleigh’s estimations of primary truss frequency on the number of panels is deduced from the inductive analysis of the set of particular trusses with an increasing number of panels. Recurrence equations that meet particular coefficients are derived using special functions of the computer algebra system Maple. Obtained solutions are polynomial, with the number of panels as variables. Rayleigh’s quotient is calculated with the assumption that the first mode of vibration is equal to truss deflection under the uniformly distributed load. Graphs of the dependencies of obtained estimations on nodes masses, the number of panels, stiffness, and size of the truss are plotted. 10.18720/CUBS.92.4 69 Truss Analytical solution Frequency Dunkerley’s method Rayleigh’s quotient Maple Symbolic induction https://unistroy.spbstu.ru/article/2020.92.4/ 9204(1).pdf
RAR RUS 9205-9205 AAD-1945-2019 57205073346 0000-0001-5415-9656 Peter the Great St. Petersburg Polytechnic University Vasilyev Ivan Anndreevich vasiliev_ia@spbstu.ru
St. Petersburg, Russian Federation
 Peter the Great St. Petersburg Polytechnic University Bortiakov Danil Evgenevich bortyakov@ratte.ru
St. Petersburg, Russian Federation
 Peter the Great St. Petersburg Pollytechnic University Grachev Aleksei Andreevich Grachev_AA@spbstu.ru
St. Petersburg, Russian Federation
 The Stress-Strain State of a Metal Cracked Plate with the Various Types of the Deformation Curve .The object of research is the effect of the deformation curve on the stress-strain state of the steel elements in the vicinity of the crack. Methods. The study is based on a finite element solution of the elastic-plastic state of a set of samples. The sample is a plate with a thickness of 0 and 20 mm with two edge cracks from 10 to 40 mm long. The results of the analysis are obtained for a bilinear strain curve and a power-law strain curve for different sample parameters. The discrepancy between the parameters of the stress-strain state in the vicinity of the crack tip for different material deformation functions is in the range from 0.3% to 4.7%. This discrepancy estimate allows you to make a decision about choosing a material deformation model for further investigation of the state of the material in the vicinity of the crack. the discrepancy graph of the parameters of the stress-strain state shows the degree of influence of the type of deformation curve within different parameters of the sample. 10.18720/CUBS.92.5 69 Deformation curve Crack Strength Material model Finite element method Plastic hardening Nonlinear fracture mechanics https://unistroy.spbstu.ru/article/2020.92.5/ 9205(2).pdf
RAR RUS 9206-9206 57191863177 0000-0001-6965-7156 Scientific and Innovation Center of Information and Communication Technologies Ravshanov Normakhmad ravshanzade-09@mail.ru
Tashkent, Uzbekistan
 57209309390 0000-0003-1351-7861 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Abdullaev Zafar Saifutdinovich abdullaev.zafar.70@mail.ru
Tashkent, Uzbekistan
 57209303933 0000-0002-8144-3406 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Khafizov Otabek Iashinovich prince0102@mail.ru
Tashkent, Uzbekistan
 Modeling the Filtration of Groundwater In Multilayer Porous Media The interaction between the surface and underground waters is often a point of interest in land reclamation, engineering hydrology, and hydrogeology. Thus, the paper deals with modeling the process of unsteady fluid filtration in a sandwich-type reservoir system. Such a study is very relevant for Uzbekistan, where these kinds of soil structures are quite common. The mathematical model of fluid filtration was developed based on partial differential equations of parabolic type with boundary conditions. An analytical solution to the problem was found using the Laplace transform. The computational experiments were carried out to determine the changes in pressure along the filtration layers' length without taking into account the elastic regime. It was found that the pressure in both layers increases exponentially. The flow of water through the interface of the filtration layers significantly depends on the piezo conductivity coefficient of a well-permeable layer, as well as on the filtration coefficient of a slightly permeable layer. There was obtained the analytical solution of the problem of fluid filtration in a sandwich-type reservoir system. The solution of the problem of determining the pressure in a weakly permeable filtration layer was found. And a new generalized formula for well gallery control was derived. The developed mathematical tool allows users to draw up the schemes of location and capacity of vertical drainage wells to protect irrigated and non-irrigated areas from flooding and protect groundwater from pollution sources, as well as isolate already contaminated areas. 10.18720/CUBS.92.6 69 Mathematical model Analytical solution Reservoir filtration Porous Medium Mass transfer Integral Laplace transform https://unistroy.spbstu.ru/article/2020.92.6/ 92062.pdf
RAR RUS 9207-9207 57226357829 0000-0003-3166-1576 Peter the Great St. Petersburg Polytechnic University Dmitriev Andrei Nikolaevich dmitriefan@outlook.com
St. Petersburg, Russian Federation
 AAH-3368-2019 56091980300 0000-0003-3850-424X Peter the Great St. Petersburg Polytechnic University Lalin Vladimir Vladimirovich vllalin@yandex.ru
St. Petersburg, Russian Federation
 LCC CADFEM CIS Novozhilov Iurii Vladislavovich vatin@mail.ru
St. Petersburg, Russian Federation
 6504372981 0000-0002-2011-000X Center of Engineering Physics, Simulation and Analysis, JSC Mikhaliuk Dmitrii Sergeevich dmitry@multiphysics.ru
St. Petersburg, Russian Federation
 Simulation of Concrete Plate Perforation by Coupled Finite Element and Smooth Particle Hydrodynamics Methods The object of research is a concrete plate subjected to high-velocity projectile impact. The finite element method (FEM) is commonly used to obtain the nonlinear dynamic response of concrete structures. However, extreme loads such as projectile impact cause large strains, damages, material fragmentations. The mesh-based FEM cannot solve this task accurately. Smoothed particle hydrodynamics (SPH) is the meshless method that allows us to solve perforation and fragmentation problems but is characterized by higher computational costs. Methods. In this paper, we use the coupled FEM-SPH method to simulate the high-velocity concrete plate perforation. This method derives from switching from FEM to SPH by specific triggering criterion.Shear strain is the triggering criterion for the concrete plate perforation problem. The elastoplastic-damage Continuous Cap Surface Model (CSCM) describes nonlinear stress-strain relationships with strain-rate dependency for concrete. Results. Validation of CSCM on quasi-static cube compression gives good agreement with Eurocode-2 data: difference does not exceed 7% in FEM and 3.8% in the SPH method, respectively. For concrete plate perforation, the best match with the experiment is for the numerical model with spacings between FE nodes, and between SPH particles are equal to 2 mm. In this case, the ratio between the projectile diameter and the spatial discretization of approximately 6:1. The triggering value of shear strain for switching from FEM to SPH seems not to influence modeling results and computing time, independently of spatial discretization. 10.18720/CUBS.92.7 69 Concretes Calibration Computer simulation Ballistics Constitutive models Strength Numerical models Finite element method Smoothed Particle Hydrodynamics https://unistroy.spbstu.ru/article/2020.92.7/ 9207.pdf