75504 2712-8172 Magazine of Civil Engineering 17 6 2024 1-119
RAR RUS 13001-13001 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University "Moscow Power Engineering Institute" Kirsanov Mikhail mpei2004@yandex.ru
14, Krasnokazarmennaya, 111250 Moscow, Russia
 0000-0002-6848-0974 National Research University "Moscow Power Engineering Institute" Luong Cong Luan luongcongluan96@gmail.com
Moscow, Russian Federation
 Simplified method for estimating the first natural frequency of a symmetric arch truss A planar model of a symmetric statically determinate arch truss is considered. The mass of the truss is evenly distributed over its nodes. The Maxwell–Mohr formula, assuming that the truss rods have the same cross-section, allows one to determine the stiffness matrix of a given structure. The Dunkerley method and a variant of the Rayleigh method are proposed to be used to estimate the first natural frequency of the truss. The mass of the structure is conditionally concentrated in its nodes. Only small vertical oscillations are considered. The generalization of a number of solutions for trusses with different number of panels to the general case is carried out by induction. A simplified method for calculating the first frequency based on the Rayleigh method is proposed. To simplify the sums of partial frequencies and squared frequencies included in the Rayleigh solution, the area of the curve limiting the frequency values is replaced by its approximate value, which is calculated by the triangle area formula. The solution includes the value of the maximum deflection of the truss from the action of a distributed load. The results obtained by different analytical methods are compared with the results obtained by the numerical method. All transformations were carried out analytically using the Maple computer mathematical system. The results showed that with an increase in the number of panels, the accuracy of the Dunkerley analytical estimate increases, and the proposed method changes insignificantly. Spectral constants and frequency safety regions were found in the spectra of a family of trusses of different orders. 10.34910/MCE.130.1 624.04:531.391.3 Dunkerley method Maple analytical solution lowest frequency regular trusses spectra of natural frequencies https://engstroy.spbstu.ru/article/2024.130.1/
RAR RUS 13002-13002 Federal Scientific Centre of Agroecology, Complex Melioration and Protective Afforestation of the Russian Academy of Sciences Suprun Veronika suprun-v@vfanc.ru
Volgograd, Russian Federation
 0009-0001-3147-6613 Federal Scientific Centre of Agroecology, Complex Melioration and Protective Afforestation of the Russian Academy of Sciences Kovalenko Ivan kovalenko-i@vfanc.ru
Volgograd, Russian Federation
 0000-0001-6490-7072 Federal Scientific Centre of Agroecology, Complex Melioration and Protective Afforestation of the Russian Academy of Sciences Ustinova Viktoriya ustinova-v@vfanc.ru
Volgograd, Russian Federation
 The GPR survey method in combination with destructive testing methods for the hydraulic structures technical condition studying The study examined the technical condition of hydraulic structures (HS) to plan their reconstruction, restoration and development of protective measures. The Sarpinskaya Watering and Irrigation System (SWIS) in the Republic of Kalmykia was the object of study. Promising research and monitoring methods were used: testing of concrete core samples using universal testing machine MIM.4-1000 and ground penetrating radar probing (by the GPR OKO-3) with ground penetrating radar survey of HS. Based on the results obtained, it can be concluded that concrete and reinforced concrete structures on the territory of the SWIS (namely, pumping station No. 1) have low strength, which is explained by their long service life and the lack of major repairs. The studied core samples collapsed under a minimum load of 116...118 kN. This indicates severe wear of the concrete coating of HS, aggravated by the close occurrence of groundwater. Further destruction of the concrete coating is inevitable, and therefore urgent repair and reinforcement of the structures are required. The data obtained will be used as a basis for conducting an examination necessary for operational monitoring of the SWIS and decision-making, when developing protective measures to strengthen the structures. 10.34910/MCE.130.2 626/627 hydraulic structures irrigation system universal testing machine GPR https://engstroy.spbstu.ru/article/2024.130.2/
RAR RUS 13003-13003 School of Civil Engineering, University Teknologi Malaysia Salih Asmaa Gheyath asmaagheyathsalih@gmail.com
Johor Bahru, Johor, Malaysia
 School of Civil Engineering, University Teknologi Malaysia Rashid Ahmad Safuan A. ahmadsafuan@utm.my
Johor Bahru, Johor, Malaysia
 Department of Water Resources Engineering, College of Engineering, University of Sulaimani Salih Nihad Bahaaldeen nihad.salih@univsul.edu.iq
Sulaimaniyah, Northern Iraq
 Effects of chicken bone powder mixed with limestone and cement on the clayey soil geotechnical characteristics Soil stabilization is aiming to enhance the geotechnical properties of soils. Traditionally, it has relied on conventional materials such as cement, and lime. However, the growing awareness of environmental sustainability has prompted researchers to explore alternatives, including waste. The employment of waste helps reduce waste deposited in landfills and decrease greenhouse gas emissions. The literature revealed that adding wastes to clay significantly improves clay’s mechanical characteristics. This study has identified alternative methods of trash disposal that would be economically and environmentally beneficial. The effect of chicken bone powder (CBP) with limestone (LS) and cement (C) on clay has been investigated. Liquid limit and plasticity index have decreased, and unconfined compressive strength (UCS) of samples treated with 10%CBP+5%LS, and 10%CBP+5%C up to 28 days have been increased by 2.69-fold and 4.82-fold respectively. A reduction in the soil’s cohesion from 37.079 kPa to 35.115 kPa and an increment in the internal frictional angle from 0.66º to 2.10º has been discovered for the mix of 10%CBP+5%LS. Compression and swell index reductions were observed with the addition of 10%CBP+5%LS and 10%CBP+5%C. From scanning electron microscopy (SEM), the binder materials caused the samples to indicate a dense and compact matrix and reduced the porosity. 10.34910/MCE.130.3 624 clayey soil soil stabilization waste chicken bone powder strength improvement unconfined compressive strength https://engstroy.spbstu.ru/article/2024.130.3/
RAR RUS 13004-13004 S-1676-2017 6507460407 0000-0002-8907-7869 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Mirsaidov Mirziyod theormir@mail.ru
39, Kori Niyoziy St., Tashkent, Uzbekistan, 100000
 M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 57221229245 0000-0002-8853-8774 Samarkand State Institute of Architecture and Civil Engineering Mamasoliev Kazokboy q-mamasoliev@mail.ru
Lolazor Samarkand, Uzbekistan
 Bending of multilayer beam slabs lying on an elastic half-space Mathematical models and analytical methods for solving contact problems of multilayer beam slabs lying on an elastic base are developed, considering the reactive normal and shear pressures of the base. In this case, an elastic filler is inserted between each pair of beam slabs. The rigidity of the filler placed between the slabs can differ in each layer. Each slab beam is subject to external loads and pressure of the filler. The stiffness coefficients of beam slabs are discrete and variable. The lower beam slab, which has a two-way connection with the elastic base, is under the influence (except for external loads) of reactive normal and shear pressure of the base. The mathematical model of the problem includes closed systems of integro-differential equations with corresponding boundary conditions. To solve the problem, an analytical method based on the approximation of Chebyshev orthogonal polynomials was used. The solution to the problem is reduced to the study of infinite systems of algebraic equations. The regularity of the resulting infinite system of equations is proven. To solve it, the reduction method was used. A test example is considered and a numerical solution to algebraic equations is obtained. The internal force factors arising in the beam slab are also investigated. Based on the analysis of numerical results, some new results were identified, i.e., a significant influence of the filler and the reactive pressure of the base on the internal force factors of the beam slab, etc. 10.34910/MCE.130.4 69 multilayer beam slab interaction half-space shear stress filler rigidity discreteness contact conditions regularity https://engstroy.spbstu.ru/article/2024.130.4/
RAR RUS 13005-13005 57194440967 0000-0003-4153-1046 Don State Technical University Nesvetaev Grigory nesgrin@yandex.ru
Rostov-on-Don, Russian Federation
 57196034514 0000-0002-2341-9811 Don State Technical University Koryanova Yulia koryanova.yi@mail.ru
Rostov-on-Don, Russian Federation
 54950122700 0000-0002-5205-1446 Don State Technical University Yazyev Batyr ps62@yandex.ru
Rostov-on-Don, Russia
 Autogenous shrinkage and early cracking of massive foundation slabs The risk of early cracking due to temperature gradients in the early period of concrete hardening of massive monolithic reinforced concrete structures determines the relevance of research into the possibilities of regulating temperature-shrinkage stresses. An important task is to improve the algorithm for calculating temperature-shrinkage stresses due to temperature gradients and autogenous shrinkage, taking into account the kinetics of heat dissipation of concrete, heat exchange conditions, and ambient temperature. Numerous factors influencing the formation of temperature-shrinkage stresses determine the relevance of the use of numerical methods for modeling temperature fields and stresses, which requires dependencies of changes in heat generation and temperature gradients over time, temperature deformations and autogenous shrinkage deformations, tensile strength of concrete, elastic modulus, creep coefficient. Purpose of the study: obtaining dependencies describing changes in the kinetics of heat dissipation and strength, taking into account the properties of cements and the presence of additives; methodology for taking into account autogenous shrinkage deformations when calculating stress values; modeling the stress-strain state of a massive monolithic structure in the early period of hardening and comparison of calculated and experimental values, taking into account the influence of autogenous shrinkage of concrete on the stress level. Materials and methods: modeling temperature fields and stresses from temperature differences and autogenous shrinkage depending on the class and kinetics of heat dissipation and hardening of concrete; experimental studies of temperature fields and stresses in the early period of hardening. Results: the equations describing the kinetics of heat dissipation, strength, and autogenous shrinkage of concrete up to 5 days old depending on concrete hardening rate are proposed. It is shown that failure to take autogenous shrinkage into account can lead to an overestimation of the tensile stress level, depending on the concrete class and the autogenous shrinkage value by up to 30 %. An algorithm is proposed for calculating the kinetics of the stress level in the early period of hardening of massive monolithic structures, taking into account the deformations of autogenous shrinkage, the class, and hardening rate of concrete. The expediency of limiting the temperature difference “center-top” depending on the required reliability in the range from 20...23 °C to 26...28 °C is substantiated. 10.34910/MCE.130.5 693.547 kinetics of heat dissipation autogenous shrinkage stress level massive monolithic structure https://engstroy.spbstu.ru/article/2024.130.5/
RAR RUS 13006-13006 B-6662-2019 57204916380 0000-0002-6877-8420 Peter the Great Saint Petersburg Polytechnic University Kozinetc Galina galina4410@yandex.ru
St. Petersburg, Russia
 Peter the Great St. Petersburg Polytechnic University Kozinetc Pavel pavelkozinetc@yandex.ru
St. Petersburg, Russia
 Peter the Great St. Petersburg Polytechnic University Badenko Vladimir vbadenko@gmail.com
St. Petersburg, Russia
 Response spectra at elevations of station dam equipment installation The object of the study is a concrete station dam of a run-of-river hydroelectric power plant (HPP). A review of publications on the methods of calculating the dynamic responses of structures is presented. The calculation studies were carried out using the finite element method. The initial data for the calculation are the physical characteristics of the concrete material, steel and rock foundation, the geometric parameters of the dam obtained as a result of engineering surveys and strength calculations of the structure. To determine the natural frequencies and vibration modes of the station dam, eight dynamic calculations of the structure and foundation system were performed for eight design nodes at the equipment installation marks. An analysis is presented describing the dam vibrations and response spectra at the equipment installation marks of the station dam. The issues of strength and stability of the station dam are not included in this study, but were taken into account when determining the geometric dimensions of the structure. To calculate the response spectra at the structure marks, a finite element model of the “structure-foundation” station dam of the Nizhne-Bureyskaya HPP was built. The construction of the calculation model was based on the geometric and physical parameters of the station dam and foundation. The accelerogram is selected in accordance with the design period of the station dam of the Nizhne-Bureyskaya HPP, which is 0.23 sec. It corresponds to the first form of oscillations with a frequency of 4.43 Hz. Using the calculated accelerogram, eight dynamic calculations of the “structure-foundation” system were performed for eight calculated nodes at the elevations of the HPP equipment installation. The solution of the equations of motion with decomposition by the initial oscillation forms was performed for each of the eight calculated nodes. The calculated nodes were determined based on the condition of the location of the HPP equipment on them. 10.34910/MCE.130.6 626 concrete station dam rock foundation earthquake natural frequency waveform finite element method response spectrum equipment https://engstroy.spbstu.ru/article/2024.130.6/
RAR RUS 13007-13007 57500684900 0000-0003-4931-2008 Moscow Timiryazev Agricultural Academy Glazunova Irina ivglazunova@mail.ru
Moscow, Russian Federation
 57218659380 0000-0003-3997-6994 Moscow Timiryazev Agricultural Academy Sokolova Svetlana sokolovasvetlana@mail.ru
Moscow, Russian Federation
 57223114050 0000-0001-8019-1203 F.F. Erisman Federal Scientific Center of Hygiene of Rospotrebnadzor Shiryaeva Margarita Shiryaeva.MA@fncg.ru
Moscow, Russian Federation
 Filtration calculation to reduce the construction impact on hydrogeological conditions in the city The paper presents the results of the research conducted to justify construction works within the intensively developed and still developing city area. The study area was located structurally and tectonically within the lowered part of the grabens bounded by regional gaps. The second from the surface aquifer was confined. The aim of the research was to evaluate the effect of lowering of the water table during construction work and laying utility lines on the filtration properties of soils, as well as on existing buildings and highways. Analytical dependencies for the infinite linear perturbation source scheme in an infinite soil layer were proposed and improved. The conducted modeling showed that the estimated maximum depression at the design point under the multi-storey non-residential administrative building was 4.4 m, which was less than the maximum allowable deformations. It was revealed that the maximum water inflows were observed at lowering of water table over the entire limited area of 20–40 m length simultaneously; therefore, the obtained analytical solution should be increased by 22.4 %. It was found that the average discharges depend proportionally on the amount of subsidence in the water table lowering area, with the relationship between the average discharges being linear regardless of the design scheme. The building subsidence due to water table lowering was calculated and a model for geofiltration calculations was developed in Microsoft Excel. The model calculations showed that the maximum subsidence of the soil at the design point of the multi-storey non-residential administrative building did not exceed the maximum allowable deformation values. 10.34910/MCE.130.7 624.131 civil engineering filtering features grounds water table drainage construction plot dewatering https://engstroy.spbstu.ru/article/2024.130.7/
RAR RUS 13008-13008 56056531000 0000-0002-9133-8546 Don State Technical University Chepurnenko Anton anton_chepurnenk@mail.ru
Rostov-on-Don, Russia
 54950122700 0000-0002-5205-1446 Don State Technical University Yazyev Batyr ps62@yandex.ru
Rostov-on-Don, Russia
 57214067410 0009-0001-6399-401X Don State Technical University Turina Vasilina vasilina.93@mail.ru
Rostov-on-Don, Russian Federation
 57194640769 0000-0003-3976-9346 Don State Technical University Akopyan Vladimir vovaakop@mail.ru
Rostov-on-Don, Russian Federation
 Artificial intelligence models for determining the strength of centrally compressed pipe-concrete columns with square cross-section The article is devoted to the development of machine learning models for predicting the ultimate load during central compression of concrete-filled steel tubular (CFST) columns with square cross-section. Artificial intelligence is currently widely used in data processing and analysis, including data on the load-bearing capacity of building structures. The use of machine learning models can become an alternative to the empirical formulas from current building design codes. The models built by artificial neural networks are based on four different architectures: cascade forward backpropagation network, Elman neural network, feedforward neural network and layer recurrent neural network. The models were trained on synthetic data obtained as a result of finite element analysis of CFST columns in a simplified formulation with varying input parameters. The input parameters of the models were the outer cross-sectional size, wall thickness, concrete compressive strength and steel yield strength. The difference from previous works is the large size of the dataset, which amounts to 22308 samples. This dataset size allows to cover the entire currently possible range of changes in input parameters. The trained models showed high performance in terms of mean squared error. The correlation coefficients between predicted and target values are close to one. The developed models were also tested on experimental data for 123 samples presented in 15 different works. The best agreement with experimental data was obtained using the layer recurrent neural network model. 10.34910/MCE.130.8 624.04 tubular steel structures concrete finite element method compressive strength artificial neural networks forecasting https://engstroy.spbstu.ru/article/2024.130.8/
RAR RUS 13009-13009 University of Thi-Qar Shakir Ressol rrshakir@utq.edu.iq
Nasiriyah, Iraq
 University of Thi-Qar Abd AL-Haleem Zainab zainababd96@utq.edu.iq
Nasiriyah, Iraq
 Evaluation of prior probability distribution of undrained cohesion for soil in Nasiriyah The objective of the study is to evaluate the prior probability distribution (PPD) of undrained cohesion (Cu) parameter for soil in Nasiriyah, southern Iraq, based on prior knowledge and observations. Estimated PPD of Cu can be used in Bayesian approach to update the observed value in any project in this region using the posterior probability distribution, because it is considered as a measure of the initial belief about a random variable before considering any data. The research used five methods to express the PPD of Cu. Two of them are for non-informative data, i.e. uniform distribution and Jeffreys prior, and three of them – for informative data, which include maximum entropy, regression analysis and subjective probability. They were applied to data collected from different sources in Nasiriyah, based on site investigation reports. The ranges of mean, standard deviation and vertical scale of Cu fluctuation were found to be 12–62 kPa, 0.5–27.6 kPa and 6–8 m, respectively. It was concluded that Jeffreys method is used well with individual models at the mean value of cohesion of 28.66 kPa and the standard deviation of 1.19 kPa. The maximum entropy can be used for the least informative data, while respecting the given constraints. The mean value of cohesion was 28.7 kPa, and the standard deviation was 1.2 kPa. Finally, for a finite number of 152 cohesion values, the subjective probability assessment approach, which takes into account expert knowledge and judgment, is the most appropriate method with the mean value of cohesion of 37 kPa and the standard deviation of 8.8 kPa. 10.34910/MCE.130.9 624 clay soil prior distribution prior knowledge site characterization undrained cohesion https://engstroy.spbstu.ru/article/2024.130.9/ 09.pdf
RAR RUS 13010-13010 6506150284 0000-0003-1139-3164 Moscow State University of Civil Engineering (National Research University) Sainov Mikhail mp_sainov@mail.ru
Moscow, Russia
 89121252975 0009-0001-9424-9661 Moscow State University of Civil Engineering (National Research University) Talalaev Nikita talalaevnicita@yandex.ru
Moscow, Russian Federation
 Cut-off wall in foundation of reservoir dam and tailing dam: comparative evaluation Cut-off wall is used to prevent seepage in foundations of embankment dams of reservoirs and tailing dams. Under the action of external loads, they may be subject to stresses comparable with strength of the wall material. There is a risk of loss of the wall both tensile strength and compressive strength. To decrease stresses, the cut-off wall is made of clay-cement concrete more deformed as compared to material concrete. To compare conditions of operation and strength of the cut-off wall in foundation of the reservoir dam and the cut-off wall in foundation of the tailing dam, there was fulfilled the study of their stress-strain state. Abstract rockfill dam 100 m high with geomembrane face was considered. A 2 m thick cut-off wall is located under the dam upstream slope: it crosses the layer of deformed foundation 15 m thick and is embedded in rock. Mohr–Coulomb model was used for description of behavior. Computations showed that the cut-off wall of the tailing dam performs in less favorable conditions than the cut-off wall of the reservoir dam. It is subject to greater by value vertical and horizontal loads. Due to pressure of slimes, it is subject to several times as much by value vertical compressive stresses. The value of stresses is highly dependent on deformation of the foundation soil. To provide strength, the deformation modulus of the cut-off wall should not exceed the foundation soil deformation modulus by more than 4 times. In spite of the fact that the tailing dam cut-off wall is subject to greater horizontal loads, it has less displacements than the reservoir dam cut-off wall. It was revealed that this is explained by more favorable stress state of soil in foundation of the tailing dam. 10.34910/MCE.130.10 626 dam cut-off wall tailing stress-strain state numerical modeling strength https://engstroy.spbstu.ru/article/2024.130.10/