75504 2712-8172 Magazine of Civil Engineering 18 3 135 2025 1-119
RAR RUS 13501-13501 57214070405 0000-0002-4502-5346 Southern Technical University Al-Mubarak A.Q.H. a.almubarak@stu.edu.iq
Basrah, Iraq
 Optimal distribution of piles under a concrete bridge abutment subject to vertical and torsion loads The transmission of torsional load from the bridge abutment to the pile foundation has a great influence on the behavior of piles The situation is worsened by the combined loading on the outriggers, such as torsion, vertical, and lateral loads. This study focuses on the importance of distributing the piles under bridge abutment subjected to torsion loads in addition to vertical loads, where a suitable distribution is found to provide better behavior of the piles. Four groups of piles were taken under the bridge abutment, each containing six piles with different distributions. Torsional and vertical loads were applied to the bridge abutment to ensure the transfer of loads with a realistic effect. ABAQUS software was used for the simulation after the experimental work. The results of different pile distributions were very from the design point of view, as it was found that the distribution of the piles under the bridge abutment must be in a multi-line shape (rectangular distribution of the piles), because it forms a rigid mass with the surrounding soil, which is able to withstand torsional loads. In addition, it is preferable to avoid using single-distributed piles, since their response is very high and the failure occurs faster than in other groups. 10.34910/MCE.135.1 624 pile group bridge abutment torsion load pile distribution ABAQUS https://engstroy.spbstu.ru/article/2025.135.1/
RAR RUS 13502-13502 57194112309 0000-0001-6184-2365 Vyatka State University Tyukalov Yury yutvgu@mail.ru Rectangular flat finite element for modeling the process of crack formation A rectangular flat finite element is proposed that allows modeling the process of crack formation without changing the initial elements’ grid. The proposed finite element can be used to calculate structures made of reinforced concrete, masonry, fiber concrete, and other materials with low tensile strength. To calculate structures with existing cracks, their position can be specified as initial data. The finite element was formed based on the stress fields approximations and the principle of possible displacements to obtain the equilibrium equations of nodes. To calculate the stiffness matrix of the finite element, the principle of minimum additional energy was used, to which algebraic equilibrium equations were added using the Lagrange multiplier method. After a crack formation in the centre of finite element, additional degrees of freedom were introduced into its nodes, determining the possible mutual displacement of the element’s parts separated by the crack. The calculations were performed for a rectangular elastic bending beam with a low tensile strength. The reinforcement was located in the tensile zone of the beam. For comparison, the beam was also calculated using standard finite elements. The comparison of the results, including the crack width, for the two solutions showed that they coincided with high accuracy. The maximum displacements differ by 1.5 %, the maximum stresses in compressed concrete and reinforcement differ by less than 1 %. The crack width for the two solutions differs by no more than 5–7 %. 10.34910/MCE.135.2 624.04 finite element method crack width tensile strength stiffness matrix possible displacements crack tip https://engstroy.spbstu.ru/article/2025.135.2/
RAR RUS 13503-13503 Novosibirsk State Technical University Gosteev Yuriy gosteev@corp.nstu.ru Novosibirsk State Technical University (NSTU) Konovalov Ilya iluhster@mail.ru
Novosibirsk, Russian Federation
 Novosibirsk State Technical University Obuhovskiy Aleksandr agd@craft.nstu.ru Novosibirsk State Technical Universit Salenko Sergey salenkosd@yandex.ru Aeroelastic vibrations of arch bridge suspensions The article identifies the causes of aeroelastic vibrations of suspensions on the arch bridge with the main span of more than 200 m. The study aims to determine the range of dangerous wind speeds and maximum amplitudes of these vibrations. This research is necessary due to intense vibrations of suspensions on the operated structure at wind speeds of 10÷15 m/s. The authors have studied models of bridge span structure and suspensions. Experimental tests as well as flow calculations using application packages have been carried out in the wind tunnel at NSTU. The study has provided verification of the vibration calculation method in the recently approved Russian regulations and comparison of the calculation with the current European method. It has been found that the cause of vibrations of the bridge suspensions is vortex-induced vibrations (VIV), while the central span of the bridge is not subject to aeroelastic vibrations. The experimental results coincide with the calculations and observations of the behavior of the suspensions of the bridge under moderate crosswind. The obtained results will be used in the future to develop methods of suspension vibration damping. 10.34910/MCE.135.3 624.21/.8 aeroelastic vibrations vortex-induced vibrations galloping aerodynamics of bridges section model cantilever model wind loads https://engstroy.spbstu.ru/article/2025.135.3/
RAR RUS 13504-13504 0000-0003-2533-9732 National Research Moscow State Civil Engineering University Samarin Oleg samarin-oleg@mail.ru Temperature mode of a room at proportional-integrated regulation of climate systems The complex including a room serviced by automated microclimate control systems, heat and mass exchange equipment of such systems and their technical means of automation is very complicated for mathematical description of transient processes under conditions of thermal disturbances when solving problems of ensuring comfort of internal meteorological parameters and synthesis of automatic control systems. The nonlinearity of the process of temperature wave propagation in the arrays of enclosing structures leads to a significant error in the case of representation of the room as a linear inertial link. Therefore, the correct mathematical description of transient processes in this case leads to nonlinear differential equations of the Emden–Fowler type, the solution of which in the considered conditions is not expressed in elementary functions and requires numerical methods. One of the most complicated variants in this case is the use of combined proportional-integral law of air conditioning system control in the absence of local heating-cooling systems. Then the solution can be obtained in a parametric form containing a generalized dimensionless parameter of the automated climate control system, including the proportional and integral components transfer factors and the air throughput of the system. The paper shows that in this case, with the growth of the integral component, the dynamic error, i.e., the largest deviation of the room temperature from the setpoint, and the control time are reduced; at the same time, for small moments of time, all the calculated curves describing the temperature behavior asymptotically coincide with the initial heating curve. After reducing the solution to a dimensionless form, the universal dependencies for the indoor temperature behavior depending on the characteristics of the room and regulator parameters, suitable for use in the engineering practice, are obtained. The calculations performed for a typical representative room, in comparison with the relevant experimental data, confirm the reliability of the obtained results and their applicability for mass design. 10.34910/MCE.135.4 697.1 : 628.8 microclimate temperature heat balance heat gain regulation proportional-integral algorithm transmission coefficient civil engineering building construction industry https://engstroy.spbstu.ru/article/2025.135.4/
RAR RUS 13505-13505 0009-0009-7697-2926 University of Baghdad Mohsen Abeer Abeer.mohsin2001D@coeng.uobaghdad.edu.iq
Baghdad, Iraq
 0000-0001-6375-4430 University of Baghdad Albusoda Bushra Suhale dr.bushra_albusoda@coeng.uobaghdad.edu.iq
Baghdad, Iraq
 Experimental evaluation of negative skin friction on floating pile in gypseous soil Gypseous soils are characterized by an open structure with developed porosity and high gypsum content, which determines their metastable state. When saturated with water, a decrease in volume occurs as a result of a decrease in matrix suction and degradation of cementation bonds, leading to rapid settlement. When a pile is installed in this type of soil, this can cause negative skin friction (NSF) along its surface, which increases the load pressure and reduces the safety factor. In this study, a laboratory model was used to evaluate NSF developed along the external surface of a steel pile embedded in gypseous soil. The effect of the degree of saturation, dry unit weight, length/diameter (L/D) ratio, and relative settlement between the soil and the pile on the magnitude of NSF, which can be described as a downward drag load along the pile shaft, has been studied. The results show that NSF increases with increasing L/D ratio by 66 % at the maximum collapse potential and decreases with increasing dry unit weight and degree of saturation by 26–60 % for L/D = 15 and by 78–137 % for L/D = 10. The maximum drag load occurs with zero water content and L/D = 15. 10.34910/MCE.135.5 69 negative skin friction NSF steel pile drag load gypseous soil https://engstroy.spbstu.ru/article/2025.135.5/
RAR RUS 13506-13506 0000-0002-3009-4293 Vyatka State University Isupov Sergei Deka_1958@mail.ru
Kirov, Russian Federation
 Composite wooden beams performance under short-term loading This paper presents an experimental and theoretical study of composite beams made of two balks connected by TGk dowel plates under short-term loading. Composite wooden beams with cross-sections and TGk dowel plate connections are a relatively new solution for building structures and are increasingly used in the construction industry, as they provide high strength and rigidity at a relatively low cost compared to glued beams. The purpose of the study is to confirm the operational strength and rigidity of composite wooden beams on TGk dowel plates, as well as to analyze the stress-strain state of the beams depending on the type of force action and the method of arranging shear ties. To achieve this goal, a target experiment was planned and carried out to test beams made of two bars for transverse load. Beams of different length, three types of transverse load, with different arrangements of shear ties were tested. The beams were destructed under short-term loading in a rather wide range of applied forces, the safety factor fluctuated within 2.13...3.95. After testing the beams using the previously developed method, calculations were performed with linear and nonlinear diagrams of joint deformation. The difference between the experimental and theoretical values of deflections is within 20 %, which quite convincingly confirms the validity of the theoretical calculations. 10.34910/MCE.135.6 624.011.1 TGK dowel plate dowel composite wooden beam test scheme strain gauges stresses beam deflection relative deformations elastic modulus https://engstroy.spbstu.ru/article/2025.135.6/
RAR RUS 13507-13507 University of Thi-Qar Younes Samar samar.y@utq.edu.iq
Nasiriyah, Iraq
 0000-0002-0556-1603 University of Thi-Qar Thajeel Jawad jawad.Thajeel@utq.edu.iq
Nasiriyah, Iraq
 University of Thi-Qar Alaa Hussein J. Al-Rkaby Alaa.Al-Rakaby@utq.edu.iq
Nasiriyah, Iraq
 Bearing capacity of square footing resting on lime-sand soil This study aims to evaluate the bearing capacity of shallow square footing resting on an artificially treated lime-sand soil layer, considering the influence of the treated layer thickness (H) and different dry unit weights of the soil layer beneath the treated layer. Additionally, the effect of lime content on the unconfined compressive strength (UCS) of lime-treated sand was also investigated. The data were obtained from loading tests carried out on a square steel plate model (89 mm length, 89 mm width, and 23 mm thick) placed on the top of an artificial lime-sand layer with H/B = 0.1, 0.3, 0.6, 1, where B is the width of the footing. The sand under the artificial layer was compacted with two dry unit weight values (14.4 and 15.8 kN/m3), thus, achieving the loose (33 %) and dense (77 %) states, respectively. Different percentages of lime (5, 7, 10, and 15 %) were added to examine the strength of treated sand soil with lime. The results showed that the increased H/B ratio affected the stress-settlement curves and improved bearing capacity with the bearing capacity ratio (BCR) rising from 1 to 2 in loose state and from 1 to 1.9 in dense state. Small scale load tests of square footing resting on lima-sand treated layer on the top of sand with different dry unit weights revealed two failure modes. For H/B = 1 with the lowest dry unit weight, the treated layer punched through to the sand soil without visible fissures until reaching the bearing capacity of the underlaying sand. For lower H/B ratios (0.1, 0.3), the lime-treated soil layer fractured, forming cracks near the footing edge and central axis, whereas higher H/B ratios (0.6, 1) resulted in cracks primarily near the footing edge. 10.34910/MCE.135.7 624 bearing capacity square footing plate load lime-sand treated layer https://engstroy.spbstu.ru/article/2025.135.7/
RAR RUS 13508-13508 0000-0002-6932-2740 Vladikavkaz Scientific Centre of the Russian Academy of Sciences Abaev Zaurbek abaich@yandex.ru
Mikhailovskoye, Prigorodny district, RNO-Alania, Russian Federation
 54950122700 0000-0002-5205-1446 Don State Technical University Yazyev Batyr ps62@yandex.ru
Rostov-on-Don, Russia
 0000-0002-9436-3691 North Caucasian Institute of Mining and Metallurgy (State Technological University) Valiev Azamat azamatva1@yandex.ru
Vladikavkaz, RNO-Alania, Russian Federation
 Nonlinear seismic response of a reinforced concrete large-panel precast building This study investigates the seismic performance of reinforced concrete large-panel precast buildings, focusing on their nonlinear response under various earthquake scenarios. The widespread use of Large-Panel Buildings (LPBs) in seismically active regions, coupled with their unique structural properties and limitations of current analysis methods, requires a more comprehensive understanding of their behavior during earthquakes. A detailed numerical model was developed to capture the complex dynamics of LPBs, including nonlinear material properties, panel-to-panel interaction, and connection behavior under dynamic loading. The research methodology used advanced computational techniques, including nonlinear time history analysis and local response examination of critical elements, with a particular focus on connection regions. The results demonstrate significant differences between traditional code-based linear analyses and nonlinear dynamic analyses, especially in predicting damage distribution and interstory drift ratio (IDR). Specifically, the nonlinear analysis revealed a concentration of damage in lower stories, with maximum IDR values of 0.282 % in the first story for high-intensity scenarios, contrasting with the code-based predictions of 0.178 % in the middle stories. Furthermore, the study identified limitations in current industry-standard software, particularly in hysteresis modeling capabilities for LPB-specific behavior. These findings underscore the critical importance of employing nonlinear analysis techniques for accurate seismic performance assessment of LPBs and underscore the need for software enhancements to better represent the unique characteristics of these structures in seismic regions. 10.34910/MCE.135.8 699.841 large-panel buildings precast reinforced concrete nonlinear dynamic analysis seismic performance evaluation https://engstroy.spbstu.ru/article/2025.135.8/
RAR RUS 13509-13509 0000-0001-6244-7965 University of Kufa Alasadi Layth Abdulrasool laitha.alasadi@uokufa.edu.iq
Al Najaf, Iraq
 University of Kufa Khlif Tagreed Hameed tagreedh.alabedi@uokufa.edu.iq
Najaf, Iraq
 University of Kufa Hassan Fadhel Abdulabbas fadhil.alshitali@uokufa.edu.iq
Najaf, Iraq
 CES-based model to predict the river rating curve Management of the irrigation scheme would be confusing in the absence of certainty in water level-discharge estimation. Accordingly, accurate flow prediction allows for more informed operating decisions in achieving the desired target of saving water. The Kufa River's rating curve was estimated using the Conveyance Estimation System (CES) in the current study. The CES outcomes were validated using the field data at specified cross-sections. The statistical indicators of BIAS, MAE, and NSE showed that the estimated rating curve and the field measurements were in reasonable agreement. Based on the findings in this study, hydraulic engineers can use the CES model as a prediction tool in the field of water engineering in making informed decisions regarding the design and operation policies. 10.34910/MCE.135.9 624.011.1 Kufa River CES model conveyance estimation system rating curve https://engstroy.spbstu.ru/article/2025.135.9/
RAR RUS 13510-13510 57216545677 0000-0002-9497-349X Kazan State University of Architecture and Engineering Kareeva Julia jkareeva2503@gmail.com
Kazan, Russia
 57202250955 0000-0001-7335-7797 Kazan State University of Architecture and Engineering Ziganshin Arslan ziganshin.arslan@gmail.com
Kazan, Russian Federation
 6602934825 0000-0003-0632-6784 V.G. Shukhov Belgorod State Technological University Logachev Konstantin kilogachev@mail.ru
Belgorod, Russian Federation
 0000-0003-3857-6980 Kazan State University of Architecture and Engineering Narsova Kseniya ksenia.bliznyakova@yandex.ru
Kazan, Russian Federation
 Characteristics of flow in the unit “elbow - supply opening” The existing literature provides formulas for standard air distribution calculations. However, the calculation coefficients are obtained experimentally for the ideal conditions of connecting air terminal devices. distributors to ducts. In practice, the design of the connection depends on the complexity of the ductwork in the building. This may affect the jet flow conditions and the air circulation in the room. The article considers the flow in the unit “elbow - supply opening” of the ventilation system. The aim of the study is to determine the dependence of the geometric and kinematic characteristics of the jet on the distance between the elbow and the supply opening. The problem is solved numerically in a two-dimensional formulation using the Fluent software package. A combination of the standard k-ε model and standard near-wall functions is used for the solution. As a result, the distribution of velocity and pressure at the outlet of the air terminal device is obtained. The dependences of the variation of the axis slope and axial velocity of the jet, as well as the kinematic coefficient of the supply opening on the distance between the elbow and the supply opening are constructed. The significant influence of the distance between the elbow and the supply opening in the unit on the kinematic characteristics of the jet is shown. The obtained dependencies should be taken into account when calculating air distribution. At distances between the elbow and the supply opening of more than 5 gauges, the characteristics of the jet tend to the characteristics of the jet flowing from the end opening. 10.34910/MCE.135.10 697.92 supply jet supply opening with elbow unit numerical study vortex zones https://engstroy.spbstu.ru/article/2025.135.10/