75504 2712-8172 Magazine of Civil Engineering 18 6 138 2025
RAR RUS 13801-13801 0009-0003-0940-372X Peter the Great St. Petersburg Polytechnic University Rigel Ivan ivan.rigel@yandex.ru
St. Petersburg, Russian Federation
57189578726 0000-0001-7051-6027 Peter the Great St.Petersburg Polytechnic University Elistratov Victor elistratov@spbstu.ru
St.Petersburg, Russia
 Numerical analysis of Arctic wind turbines supporting structures The paper presents numerical modeling methods for the supporting structures of wind turbines operating under Arctic conditions on permafrost soils. The relevance of the research is determined by the strategic priorities for the development of the Russian Arctic zone and the need to consider the specific environmental and climatic conditions in the energy infrastructure design. An integrated methodology is developed for analyzing the structural behavior of Arctic wind turbines, including the stress–strain state and dynamic response of the supporting structures finite element modeling, accounting for wind and operational loads, nonlinear soil–structure interaction, thermal regime, and temperature-dependent soil properties. The methodology is tested through a case study of a 100 kW wind turbine with a 30 m tower and a 24 m rotor diameter, for the Yamal-Nenets Autonomous Okrug environmental conditions. The results show that the permafrost degradation leads to increased displacements and stresses in the structural system by up to 25 % and reduces the structure natural frequencies by up to 10 %, due to a local 70-fold decrease in reactive soil resistance. The identified factors should be considered in the Arctic wind turbines design to ensure accurate assessment of structural performance and resonance risks. 10.34910/MCE.138.1 624.97 Arctic wind turbine environmental conditions supporting structures numerical modeling stress-strain state dynamic response permafrost degradation ground reaction forces https://engstroy.spbstu.ru/article/2025.138.1/
RAR RUS 13802-13802 0009-0006-3520-0717 Department of Civil Engineering, Sharif University of Technology Fallah-Mehrjardi Kiavash kiavashfallah@gmail.com
Tehran, Iran
 Department of Civil Engineering, Western University Shariat Afagh sshari56@uwo.ca
London, Ontario, Canada
 Isfahan University of Technology, Isfahan University of Technology Eftekhar Mohammad Reza eft@iut.ac.ir
Isfahan, Iran
 Optimizing concrete mix design with a high percentage of microsilica: Enhancing strength, Sustainability Microsilica is a highly reactive pozzolanic material widely known for improving the strength and durability of concrete. In this study, we explored how replacing 10%, 20%, and 30% of cement with microsilica affects the performance of lightweight concrete over 7, 14, and 28 days. The concrete mixes were prepared using a blend of natural and artificial lightweight aggregates with cement content ranging from 350 to 550 kg/m3. To ensure good workability, a 2% modified lignosulfonate-based superplasticizer was used, and water-to-cement ratios varied between 0.30 and 0.45. Along with compressive strength, we also measured the modulus of elasticity, specific weight, and water absorption under both dry and wet conditions. The results clearly showed that higher levels of microsilica led to notable gains in strength and elasticity, while also reducing the weight and water absorption of the concrete. The most effective mix combined 30% microsilica with a cement content above 500 kg/m3, delivering excellent mechanical performance and durability. These findings highlight the potential of microsilica not only to enhance structural quality but also to reduce environmental impact by lowering cement usage. This study supports the thoughtful use of microsilica as a sustainable and performance-boosting material in modern concrete design. 10.34910/MCE.138.2 624 compressive strength microsilica light artificial aggregate modulus of elasticity water absorption https://engstroy.spbstu.ru/article/2025.138.2/
RAR RUS 13803-13803 6701544758 0000-0002-1756-3526 National Research Tomsk Polytechnic University Vakalova Tatiana tvv@tpu.ru
Tomsk, Russian Federation
 57222054169 0000-0002-7656-5628 National Research Tomsk Polytechnic University Sergeev Nikolay axioma-13@yandex.ru
Tomsk, Russian Federation
 0000-0001-8242-0655 National Research Tomsk Polytechnic University Tolegenov Dias www.dika-92@mail.ru
Tomsk, Russian Federation
 7801463567 0000-0003-4184-1554 National Research Tomsk Polytechnic University Revva Inna revva@tpu.ru
Tomsk, Russia
 Phase formation, structure and properties of ceramic materials based on binary mixtures “refractory clay – steel slag” The work is devoted to the current problem of creating high-strength ceramic materials using techno-genic waste. This problem is solved by using refractory clay as the main raw material component with the addition of high-iron calcium silicate steel slag in various proportions. The processes of phase formation that occur during heating of steel slag are considered. It has been established that the use of steel slag to produce ceramic materials is possible only if the destructive effect of dicalcium silicate formed in the slag at firing temperatures above 1000 °C is neutralized. This is possible due to the chemical transformation of dicalcium silicate into other calcium-containing minerals that are safe from the point of view of molded sample destruction, such as anorthite, wollastonite, gehlenite, and others that do not have polymorphism. Compositions of ceramic masses have been developed that ensure the production of high-strength anorthite ceramics (with water absorption from 2.8 to 13.4 % and compressive strength of up to 200 MPa) for a wide range of purposes – structural (wall) building ceramics, clinker building ceramics, ceramic proppants, etc. 10.34910/MCE.138.3 691.43 refractory clay steel slag sintering mechanical strength gehlenite anorthite building ceramics https://engstroy.spbstu.ru/article/2025.138.3/
RAR RUS 13805-13805 College of Engineering, Al-Nahrain University Hameed Mohammed st.mohammed.a.h.f@nahrainuniv.edu.iq
Baghdad, Iraq
 Al-Nahrain University Daud Raid raid.a.daud@nahrainuniv.edu.iq
Baghdad, Iraq
 Finite element analysis of fatigue damaged reinforced concrete one-way slabs repaired with CFRP sheets In twenty-eight samples in this study, the structural behavior of fatigue-damaged one-way slabs was produced using a nonlinear finite element model that was created using ABAQUS. The effect of carbon fiber-reinforced polymer (CFRP) parameters and fatigue-damaged percentages is examined to obtain a better reaction. The full model accounts for the elastic and plastic behavior of the materials and uses three-dimensional parts (solid, shell, and truss). To investigate the accuracy of the model, the authors' experimental data (monotonic and fatigue damage) is used to validate the numerical outputs. For the four verified slabs, the average and coefficient of variations for ultimate load of finite element analysis to ultimate load of experimental work were 0.997 and 5.35 %, respectively; for the deflection of finite element analysis to deflection of experimental work, they were 1.197 and 15.99 %, and for energy absorption, they were 1.134 and 12.2 %, respectively. Twenty-four samples parametric studies using the impacts of CFRP sheet thickness, CFRP sheet modulus of elasticity, CFRP sheet length, the concrete compressive strength value, and the fatigue damage percentage. Examining these metrics was intended to provide insight into the efficacy and structural performance of the employed fortification technology. The numerical findings demonstrated that the technique of externally bonding CFRP sheets to strengthen damaged slabs may be regarded as a successful, and cost-effective method. 10.34910/MCE.138.5 624 ABAQUS fatigue damage EBR CFRP sheet one-way slab https://engstroy.spbstu.ru/article/2025.138.4/
RAR RUS 13806-13806 57339740900 0000-0002-0373-8655 Russian State Agrarian University – Moskow Timiryazev Agricultural Academy Naumova Anna koshevaya81@mail.ru
Moscow, Russian Federation
 0000-0003-2094-2882 A.N. Kostyakov Federal Scientific Center for Hydraulic Engineering and Land Reclamation Ilinich Vitaliy vilinitch@gmail.com
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
 Neural network modeling for real-time water quality assessment In recent decades, water quality problems have become even more pressing due to population growth, industrial expansion, and climate change. A number of studies by foreign researchers have shown the results of applying neural networks. There are studies confirming the reliability of water quality prediction results generated by neural networks. During the work, OpenAI Earth Pro, Microsoft Excel, a water flow sensor based on the Arduino UNO board with author’s modifications (tail feathers and a built-in plugin for calculating flow velocity), Python, Tensorflows Keras 2.2.0, Scikit-learn, Pandas libraries for machine learning and developing the neural network architecture were used. Two neural network models were combined to build a hybrid neural network model for predicting water quality parameters in the research. Neural network models provide unique opportunities to improve water resource management at various levels, from local to global. One of the key advantages of such models is the ability to adapt to specific conditions and requirements, providing more accurate predictions and timely decision-making in the face of uncertainty. The relevance of the work is due to the application of neural networks for predicting water quality can contribute to improving the early warning system for pollution, optimizing operational processes at water treatment plants, and developing effective strategies for water resource management. During the research, an innovative hybrid neural network model for predicting water quality parameters was developed, based on the integration of a deep convolutional neural network and a bidirectional recurrent neural network, which consists of three functional parts. 10.34910/MCE.138.6 69 neural network Tensorflows Keras 2.2.0 watershed water water flow negative impact water quality water resources optimization’s algorithm https://engstroy.spbstu.ru/article/2025.138.5/
RAR RUS 13807-13807 57205429154 0000-0002-7115-1629 Tyumen State University Gilmanov Aleksandr a.y.gilmanov@utmn.ru
Tyumen, Russian Federation
 57194441481 0000-0002-2757-1386 Tyumen State University Grigoriev Boris b.v.grigoriev@utmn.ru
Tyumen, Russian Federation
 37013734300 0000-0003-0017-4871 Tyumen State University Shevelev Aleksandr a.p.shevelev@utmn.ru
Tyumen, Russian Federation
 Tyumen State University Vazhenin Denis d.a.vazhenin@utmn.ru
Tyumen, Russian Federation
 Physical and mathematical model of a settling tank with thin-layer modules The presence of fine impurities in industrial water complicates the operation of fine water purification systems. To solve this problem, thin-layer settling tanks have become widespread in industry due to their high consumption characteristics. Depending on the application and the consumer, the maximum permissible concentrations of dispersed particles can vary in wide ranges. Optimizing the operation of a thin-layer tank requires conducting field experiments in laboratory and industrial installations. Mathematical modeling allows to reduce the number of experiments. The aim of the work is to develop a mathematical proxy model of a settling tank with thin-layer modules, which for the first time considers the influence of the concentration of coagulant and alkali on the particle size distribution, as well as salinity on the particle deposition rate. This model is based on simplified laws of conservation of mass and momentum in the hydraulic approximation. To study the effect of the parameters of the settling tank and reagents on the concentration of dispersed particles at the outlet, experiments were planned and conducted on a laboratory installation in a wide range of changes in these parameters. The values of the concentration of dispersed particles at the outlet at different angles of inclination of the plates, their quantity and concentrations of coagulant, alkali, and salt were obtained. The simulation results are compared with experiments, and their satisfactory agreement with each other is shown with an average error of 3 %. Based on the sensitivity analysis, ranges of parameters of the settling tank and chemical reagents were determined, for which the mathematical model gives representative results. It was found that with an increase in the concentration of chemical reagents, the proportion of particles with sizes less than 100 μm in the stream decreases, which leads to an increase in the degree of water purification. 10.34910/MCE.138.7 628.16.06 settling tank thin-layer modules hydraulics mathematical model experimental installation plate tilt angle substance concentration coagulant salinity validation https://engstroy.spbstu.ru/article/2025.138.6/
RAR RUS 13808-13808 57208687018 0000-0002-7580-5669 Peter the Great St. Petersburg Polytechnic University Murtazin Ilnar murtazin_ir@spbstu.ru
St. Petersburg, Russian Federation
 0000-0002-2115-1751 Peter the Great St. Petersburg Polytechnic University Fedorenko Roman fedorenko_rv@spbstu.ru
St. Petersburg, Russian Federation
 Lukin A;exei lukin@compmechlab.com Modestov Victor modestov@compmechlab.com TEKHNOARM+ Malinkin Andrey mas193cm@mail.ru
St. Petersburg, Russian Federation
 TEKHNOARM+ Fedotov Mikhail domzagorodom@mail.ru
St. Petersburg, Russian Federation
 TEKHNOARM+ Panarin Sergey tekhnoarm@mail.ru
St. Petersburg, Russian Federation
 Parameter identification of the concrete damaged plasticity model The article is devoted to the development of methods for identification and validation of the parameters of the "Concrete Damage Plasticity" material model based on experimental studies. During the experiments, prismatic samples were tested for sign-constant cyclic load after preliminary heat treatment at various temperatures. According to the test results, the temperature dependences of the mechanical properties were established: the conditional proportionality limit, the ultimate strength, Young's modulus, and the scalar damage variable. Piecewise analytical envelopes were used to plot the stress-strain curves, which describe linear, inelastic, and descending parts. Accumulated concrete scalar damage variable during compression is determined based on the elastic modulus degradation analysis at each loading cycle. Parameters of analytical approximations are determined directly through experimental data or using numerical identification method based on an iterative process of searching for the minimum functional. The structure of the minimized functional contains auxiliary subfunctions due to well-known statistical indicators: the standard deviation of the compared values, the linear correlation coefficient, and the area under the compared dependencies. The search for the minimum of the desired value is carried out using the gradient descent method according to the criterion of the minimum contribution of the sum of three subfunctions. At the last step of the study, the obtained model is validated based on the calculation for uniaxial and cyclic loading of a single-element prismatic sample in the ABAQUS FEA. The developed calculation method makes it possible to complete the loading cycle at any axial force value, including zero, as well as to continue the next loading cycle from the current stress state. The considered method for validating the inelastic deformation model for concrete is characterized by its consistency and versatility. The results demonstrate sufficient accuracy in approximating uniaxial and cyclic stress-strain curves, and the proposed approximation relationships are free from ambiguity when converting the inelastic part of strain to plastic one. 10.34910/MCE.138.8 539.3 parameter identification stress-strain curve cyclic loading concrete damage analytical approximation ABAQUS https://engstroy.spbstu.ru/article/2025.138.7/
RAR RUS 13809-13809 0009-0002-4300-5277 School of Civil Engineering, Wanjiang University of Technology Lu Hongbin 176855347@qq.com
Maanshan, China
 0009-0007-7030-7269 School of Civil Engineering and Architecture, Anhui University of Technology Song Shaohui Songsh1999@163.com
Maanshan, China
 0000-0002-3522-3074 School of Civil Engineering and Architecture, Anhui University of Technology Xiang Guosheng xianggsh2011@163.com
Maanshan, China
 0009-0005-2597-2214 School of Civil Engineering and Architecture, Anhui University of Technology Wang Xinxin x15686201208@163.com
Maanshan, China
 0009-0004-0690-7313 School of Civil Engineering, Wanjiang University of Technology Luan Mengyuan 2647426899@qq.com
Maanshan, China
 The expansion deformation characteristics of expansive soil under acid pollution Soil pollution incidents occur frequently in China. After contamination by acid, the expansion performance of expansive soil is further intensified, posing a significant threat to infrastructure. Using sulfuric acid as the contaminant source, expansion deformation tests of expansive soil under sulfuric acid immersion were conducted, followed by scanning electron microscopy and X-ray diffraction analyses to investigate the evolution of the microstructure and mineral composition of the samples under acidic conditions. The results demonstrated that the acidic environment increased the expansion rate of the samples, with higher sulfuric acid concentrations correlating to greater expansion rates. Under acidic conditions, cementing materials (e.g., free oxides) in expansive soil underwent varying degrees of dissolution and leaching, thereby weakening the connections between overlapping structures. This process resulted in a more dispersed arrangement of the surface-overlapping structures, accompanied by a continuous increase in both the volume and number of micropores. The post-acid-rain expansion deformation of expansive soil can be quantified using the e–pe fractal relationship. Furthermore, the e–pe fitting analysis of the experimental data revealed that the enhancement of expansion performance by acid rain primarily stems from the reduction in cementing content, leading to an increase in the expansion coefficient (κ). 10.34910/MCE.138.9 624 expansive soil acid rain swelling deforming fractals acid pollution https://engstroy.spbstu.ru/article/2025.138.8/
RAR RUS 13810-13810 National Institute of Technology Kumar Ashok ashokkumar.civil@nitjsr.ac.in
Jamshedpur, India
 National Institute of Technology Kumar Virendra virendrakumar.ce@nitjsr.ac.in
Jamshedpur, India
 National Institute of Technology Kumar Sanjay sanjaykumar.civil@nitjsr.ac.in
Jamshedpur, India
 National Research University “Moscow State University of Civil Engineering” Orlov Alexandr orlovak@mgsu.ru
Moscow, Russian Federation
 Khalifa University of Science and Technology Dixit Saurav sdixit@ricssbe.edu.in
Abu Dhabi, United Arab Emirates
 Ternary blended concrete synergy of mineral admixtures Concrete that uses supplementary mineral admixtures offers a route to reduce clinker use while maintaining performance, yet the combined action of multiple admixtures in one binder remains uncertain. The potential for synergy among metakaolin (MK), fly ash (FA), and rice husk ash (RHA) has been emphasized in prior work as a means to enhance packing and pozzolanic reaction. The gap addressed here is the absence of a practical way to quantify the combined efficiency of MK–FA–RHA and to predict strength across a broad range of ternary blends. The objective is to evaluate ternary MK–FA–RHA concretes and to derive synergy/efficiency-based equations to predict compressive strength and to correlate it with split tensile and flexural strength. An M25 mixture with water/binder 0.45 and 39 combinations (MK 6–8 %, FA 5–15 %, RHA 5–20 %) was produced; slump, compressive strength (7, 28, 56 days), split tensile and flexural strength were measured using IS:516 specimens (150 mm cubes, 75×150 mm cylinders, 100×100×500 mm beams). Workability decreased with increasing fines: at MK 7 %, the slump fell from 188 mm to ≤100 mm as FA and RHA rose, and reached 35 mm at MK 8 %, FA 10 %, and RHA 20 %. Strength responses showed that 8 % MK alone raised 28- and 56-day compressive strength to 37.24 and 41.76 MPa (vs 34.87 and 38.87 MPa for the control), while RHA ≥15 % produced 15–30 % lower 28-day strength; the best ternary blend across all mixes was 8 % MK + 10 % FA + 10 % RHA. Regression-based equations that incorporated a synergy factor accurately reproduced compressive strength, with most errors within 0–10 %, and yielded R2 values of 0.73–0.82. Companion correlations predicted split tensile and flexural strengths from compressive strength. These findings suggest that MK 8 % with FA and RHA at 10 % each balances clinker reduction and strength, although high RHA contents require rheology control to avoid consolidation-limited results. Future work is recommended on durability mechanisms and admixture optimization to extend the predictive framework. 10.34910/MCE.138.10 691.3 ternary blended concrete workability compressive strength synergy efficiency factor https://engstroy.spbstu.ru/article/2025.138.9/