The technical condition of bridge structures (bridges, overpasses and others) on highways has been the subject of research for a large number of works in recent years. This technical condition changes over a long time, and in some cases (emergencies, military operations, sudden failures) – very quickly. In such situations, accelerated restoration of traffic on these transport facilities is required. Often, bypassing these bridges is impossible or difficult for a number of reasons: economic, time, social, technical and others. The classical methods of restoring objects (the construction of a new structure or the reconstruction of an existing bridge) are very long in time and laborious or technically complicated. In such cases, solutions are needed to restore damaged bridge structures in accelerated formats. The choice of a specific method should be made according to the appropriate methodology for assessing efficiency, taking into account, first of all, the recovery time, the availability of resources and capabilities, the cost, as well as a number of other points.
This article presents this method, based on the analysis of existing recovery methods, and draws the appropriate conclusions. During the development of the method, performance criteria (indicators) and their interval and mean values were adequately substantiated and proposed. In addition to the proposed methodology for assessing efficiency, the results of the work resulted in conclusions made on it about the most appropriate ways to restore bridge structures with an accelerated resumption of traffic on them. The scope of the study results may be solutions for emergency situations at transport facilities.

Maintenance is one of the most important work packages to be carried out during the life cycle of roads and their construction. The timely and high-quality completion of all required maintenance work allows for the maintenance of the standard operating structure and extends the period between repairs. Timely and high-quality work cannot be carried out without the required level of funding. Justification of the necessary and sufficient level of funding is based on detailed maintenance planning. One of the planning tools is a maintenance project, which shows the specifics of the specific object, defines the requirements for the operational condition of its elements, composition, amount and frequency of major works, technical resources, which are necessary to achieve these types of work, the annual maintenance costs of the facility.
The complexity of designing the maintenance project for unique bridge structures is primarily due to the unusual design elements, their saturation and lack of experience with such designs. In addition, there are a number of shortcomings in the existing technical, cost and methodological documentation governing the maintenance of bridge structures, caused by various reasons: some documents are out-dated, some issues of maintenance are missing in existing documents, some of the documents have contradictory explanations.
This article analyzes the existing normative, technical, methodological and budget documentation regulating the maintenance of bridge structures, gives recommendations for its improvement, summarizes and analyzes the authors' experience in developing projects for the maintenance of unique bridge structures, described the difficulties faced by developers of content projects, described their possible solutions.

To reduce the dynamic response of superstructures from the impact of a moving load, one of the main methods used in the established practice is to regulate the mass of superstructures, as a rule, in the direction of increase. In this approach, an important role is played by the analysis of dynamics of the rolling stock – superstructure system. Another way to reduce the dynamic response of the rolling stock-superstructure system is to install special damping devices, both passive and active. The use of an active damper makes it possible to achieve maximum effect in reducing vibrations, however, the design of such a damper has a certain complexity, is expensive and unreliable in operation. Currently, it is more economical to use passive type dampers with self-contained properties.
The article discusses various options for using dynamic vibration dampers in different systems. The goal of the research is to predict and optimize the use of these dampers in order to minimize any negative effects on bridge structures.
Vibration isolation systems that use dynamic vibration dampers can achieve maximum efficiency if key control parameters are carefully selected and optimized. These parameters include: the frequency range, the ratio of tuning frequencies, the amount of damping, and the number of dampers used in the vibration isolation system for the bridge. If these parameters are not selected correctly, the system may not function optimally and may not provide the required level of vibration reduction. To optimize these parameters, the vibration dampers should be placed symmetrically relative to the center of the bridge, with a certain spacing.
Based on the analysis, it is shown that the effectiveness in reducing bridge responses decreases with increasing interval between dampers and when installed further from the middle. The most massive damper is located in the middle of the span, and as you move away from the center, the mass of the dampers decreases. The maximum number of dampers is determined by the length of the bridge and the pitch of their installation. It is important to note that as their number increases, the optimal values of the tuning range and frequency ratios increase.

This paper considers the peculiarities of strength calculation of reinforced concrete railway bridges under moving load and moving oscillator. Finite element and finite difference methods are used.
One span girder is considered, which is modelled by a Timoshenko girder with regard to prestressing. The point of contact between the beam and the support and the fixed and movable joints at the points of contact with the support are taken into account.
The 23.6 m long spans were taken as an example for the study of a railway bridge. In the numerical solution of the problem of oscillations of a system with distributed parameters under the action of a moving concentrated force and mass, parasitic oscillations were established by selecting the time step depending on the speed of load movement. Calculations were performed using an implicit Newmark scheme for a moving concentrated force at a velocity of 25 m/s with a time step of 0.008 s; at 50 m/s with 0.004 s; at 75 m/s with 0.00267 s; at 100 m/s with 0.002 s; and at 200 m/s with 0.001 s.
Vibrations of the system bridge – mobile load were investigated. The study was carried out on the example of a Talgo locomotive as a moving load or mass. The velocity of the moving load below which the travelling force model can be used was determined. With increasing horizontal speed of the oscillator the deflection of the girder increases, also the vertical oscillation of the mass increases.

This article examines some of the complex natural factors that must be taken into account when designing bridge supports built across the mouths of small watercourses and railway tracks running along the pressure sections of the shores of the seas. Pressing areas are defined as places where the earthbed is bounded on one side by steep slopes, and on the other by the sea or watercourses that do not have coastal terraces. The issues of engineering protection of bridge supports and the roadbed of transport structures that are exposed to the most unfavorable combination of hydrological phenomena – river flooding and sea storm surges of rare frequency – are considered.
The research was carried out using the method of physical modeling. Physical modeling of coastal and riverbed processes was performed in a deep-sea wave basin. The simulation is performed at a scale of 1 : 40. At the same time, the simultaneous passage of a flood on a river of 1% availability and a sea storm with a repeatability of 1 every 25 years was reproduced. The stability of the protective wave-damping band in the estuary region was assessed. A variant of the layout of nano-retaining structures and a wave-extinguishing strip with the width necessary to dampen the rolling energy in order to protect the roadbed was investigated.
The purpose of the research is to assess bottom deformations in the estuarine zone under the simultaneous influence of storm waves and a river stream of a calculated flood.
According to the results of physical modeling, deformations of profiles in the estuarine part of the river and in the estuarine zone of the sea were obtained. The model defines the zones of erosion and accumulation of material removed from the riverbed by flood waters. The bottom deformation model (change in depths) and, as a result, the change in wave heights and the location of wave collapse should be taken into account when calculating the parameters of engineering protection structures for bridge crossings.
The research results can be used to correct mathematical models of hydrodynamic processes in the coastal zone of the seas near the mouths of watercourses.

The service life of major road bridges can reach 50 years or more without major repairs aimed at improving their operational reliability. As a result, the technical condition of such structures varies significantly, with most of them being in poor condition.
One of the main issues is the discrepancy between the design and actual load-bearing capacity of bridge structures, as well as the lack of operational methods for assessing their load-bearing capacity in the field. This is particularly critical when it comes to allowing vehicles, military equipment, or special vehicles to pass through bridges that have been damaged. These factors necessitate the development of simplified methods for approximately determining the load capacity and conditions for safe passage of vehicles.
This article proposes a methodological approach for the operational assessment of the load capacity of reinforced concrete bridge spans. The essence of the methodology is to determine the load capacity by calculating the maximum bending moments in the beams, taking into account the constant and temporary loads. To simplify the calculations, the authors have developed special graphical dependencies that allow for the assessment of load capacity based on visual inspection data without the use of complex mathematical models.
This methodological approach can be applied by military engineers for an accelerated assessment of the load capacity of bridge spans in the field. It allows for a quick analysis of the technical condition of bridge spans and the decision-making process regarding the possibility of passing vehicles, which is particularly important in emergency situations or military operations.

Ensuring the normative condition of road networks and the artificial structures on them is one of the priority tasks of the Transport Strategy of the Russian Federation until 2030 and the National Project ‘Safe and High-Quality Roads’. The increase in traffic intensity on the roads of the Russian Federation, especially in the direction of the southern regions, imposes increasingly stringent requirements on their technical condition. The technical condition of both newly built bridge structures and those that were brought to standard condition through repair and restoration work will further depend on the timely measures taken to repair, overhaul or reconstruct them.
The purpose of this study was to examine existing tools for collecting initial data on the technical condition of bridge structures or a fleet of bridge structures, identify the pros and cons of existing databases for storing and processing information on artificial structures, and determine methods for predicting technical conditions based on long-term monitoring to enable the most rational planning of costs for their maintenance.
The article presents the main stages of forecasting the costs of maintaining artificial structures, modern technologies for collecting initial data, their advantages and disadvantages relative to traditional ones, considers the main possibilities and disadvantages of existing databases for storing and processing information about structures, proposes methods for forecasting the development of defects in artificial structures based on long-term monitoring data, mechanisms that allow optimizing costs for the period of maintenance of artificial structures due to the forecast of the development of defects over time for a specific park of artificial structures.

The issues of enhancing traffic safety on bridges remain consistently relevant. Maintaining the high operational condition of transportation structures under adverse weather conditions, particularly during winter, is crucial. Bridges are considered ‘colder’ compared to road sections, with slipperiness forming more frequently on them, anti-icing technologies for bridges have distinct characteristics.
The research aims to identify structural features of bridges influencing winter slipperiness formation and develop methods for its prediction to improve traffic safety. Analysis shows that bridges, unlike road segments, exhibit lower surface temperatures due to the absence of a soil base, multilayered material composition, and high thermal conductivity, leading to increased ice formation. Experimental methods, including sensor measurements from automatic road weather stations (ARWS), and specialized calculations based on solving non-stationary heat conduction equations with boundary conditions accounting for bridge design specifics, can determine pavement temperature regimes.
The paper describes and analyzes technical systems used for weather monitoring of artificial structures both internationally and in Russia. Installation specifics of road sensors integrated into ARWS on bridges, associated challenges, and solutions are examined. The necessity of developing ice formation warnings based on sensorderived data is emphasized.
A physical formulation of the problem regarding bridge temperature regime formation under external factors is presented. A mathematical model for calculating bridge pavement temperature is proposed, represented by a nonstationary heat conduction equation for multi-layer structures, with boundary condition peculiarities described. Further research objectives are outlined.

This article presents the results of work carried out by students belonging to the Transport Structures research group at the Mukhamedzhan Tynyshpaev University ALT. Under the guidance of I. S. Bondar, the students built a lever loading test bench in the laboratory. A metal I-beam was used as the test specimen, to which strain gauges were attached in the middle of the span using cyanoacrylate adhesive in a half-bridge connection. The metal beam was loaded with weights ranging from 2 to 5 kg, which were hung on the lever system. The TENZO measuring complex was used to process and read the readings and strain gauges, allowing real-time relative deformations to be obtained for each strain gauge. The TENZO program automatically plots graphs of relative deformations and stresses. Next, students use Microsoft Excel to plot a graph of the stress state of the beam span structure model. The use of a strain gauge software and hardware system in the educational process helps students and master's students in engineering specialties to conduct research related to the strength of structural materials in laboratory conditions that are safe for students.

The article is devoted to the study of cable-stayed structures in bridges and analyzing the causes of their collapse. Cable-stayed bridges, due to their elegant shape and high strength, are widely used in modern construction, but their collapse is a serious problem for the engineering community. This paper discusses the main design features of cable-stayed bridges, their advantages and disadvantages, and the factors contributing to their collapse. The analysis of the causes of the collapse of the arch span of the Nanfanaon Strait Road Bridge in Suao City, Yilan County, Taiwan includes a study of historical collapse cases, which reveals common patterns and causes such as design errors, inadequate maintenance, natural factors, and human factors. Cases where structural defects caused by material fatigue or improper operation lead to catastrophic consequences are also considered.
The paper presents a methodology for condition assessment of cable-stayed structures, including the use of modern technologies such as unmanned aerial vehicles (UAVs) and real-time monitoring systems. Special attention is given to recommendations for improving the design and operation of cable-stayed bridges, which can significantly reduce the risk of collapse.
Thus, this study not only emphasizes the importance of understanding the causes of collapses, but also offers practical solutions to improve the safety of cable-stayed structures, which is critical for the future of bridge engineering, and is also important for improving the reliability of cable-stayed bridge structures in the future. In order to prevent dangerous situations in advance, it is necessary to conduct inspections and tests of bridge structure elements in accordance with the plan, using specialized equipment and instruments, as well as to install monitoring systems.

Regulatory standards for permissible deviations in anchorage zones of prestressed elements often fail to account for the dimensions of indirect reinforcement, the geometric parameters of anchors, or the actual loadbearing capacity of the zone transferring forces from the anchor to the concrete.
This article presents a case study on determining the permissible misalignment tolerance between spiral indirect reinforcement and the OS-55 (55-strand) cup-type anchor supplied by STS Ltd., a prestressing system provider. The anchor is used in the prestressing system of nuclear power plant (NPP) containment structures. Additionally, the study examines the permissible deviation of indirect reinforcement in the OS-19 (19-strand) anchor, commonly found in bridge structures. A real-world example of anchorage zone failure in a prestressed concrete beam from a civil engineering project is provided, demonstrating how excessive misalignment between the spiral reinforcement and anchor led to structural damage–highlighting the relevance of this research.
A review of domestic and international regulatory documents is presented. Finite element analyses were performed to evaluate load transfer zones from prestressing anchors to concrete under varying degrees of spiral reinforcement misalignment relative to the anchor axis.
Analysis and comparison of calculation results for the OS-55 anchorage zone, implemented in actual projects, showed that the permissible misalignment tolerance could be more than doubled compared to current regulatory limits. For the OS-19 anchorage zone, finite element analysis confirmed the permissible spiral displacement limits specified in standards. Any increase in this tolerance is only permissible if rigorously justified by additional verification.

The article presents the results of the digital twin technology approach development for artificial structures (hereinafter referred to as DSS) on the Russian Railways railway network. The term of the ISSO digital twin is formulated. Based on the analysis of existing developments, the problems in the implementation of the ISSO digital twin technology are highlighted. The disadvantages of using monitoring systems and the Internet of Things are noted. A specialized constructor algorithm is proposed for creating digital information models based on available information in automated systems of the railway infrastructure of Russian Railways. This algorithm uses several basic elements to create a bridge structure: a bridge bed, a superstructure, supporting parts and supports. The modeling of the elements themselves is provided in the most automated mode: data is integrated from available sources – automated systems, as well as a database in the form of a typical bridge structure catalogue. Data categories have been formed to fill in the information in the attributes of the information model: normative, design and diagnostic. An algorithm for the integration and analysis of monitoring system data is described, as well as their comparison with regulatory information. The obtained results can become the basis for creating a new system for managing the condition of artificial structures on the country's railway network.