Costs planning and ways to improve bridge operation service

Repair and reconstruction is an integral part of the life cycle of such structures as: bridges, overpasses, aqueducts. Timely maintenance and repair of bridge structures contributes to the continuous improvement of their technical level, as well as to the operational state with increasing load and intensity over time on constantly under construction highways. This article presents the results of a study of the need to repair structures over time. The article contains a description of the types of work, as well as the terms when these works need to be performed, graphs of the volume and cost of work are given. As materials and initial data, the data of approximate turnaround periods of elements of bridge structures were taken, as well as a table of the frequency of repairs by year was compiled. Based on the collected data, graphs of the cost and changes in the volume of work were built over time. In addition, graphs of the cost of repairing individual elements of the structure are given in relation to the total cost of the structure. Based on the results obtained, recommendations are formulated for planning the repair of expatriated bridge structures by bridge maintenance departments. A set of measures is also proposed to eliminate existing violations and further operation of the bridge structure. A set of works for the repair of individual units and structures is recommended. Arguments are given for the need to share responsibilities between bridge operation departments during the repair of the structure.

Development of a system for control of electric energy parameters in the distribution network

Background: The creation and distribution of technical means and complexes aimed at building effective control systems for electrical networks using information that can be collected by modern metering devices, as well as organizing work in an automated mode, is an urgent task at the present stage of development of the electric power industry in Russia and in the world. Aim: The research presented in this article is aimed at creating an effective system for monitoring the parameters of electrical energy in distribution networks of low and medium voltage levels. Methods: The study was carried out using the theoretical foundations and basic laws of electrical engineering, as well as methods of computer modeling and CAD. Results: A description of the developed system is given, the applicability of its use is graphically shown and substantiated in writing, the possibilities and prospects of application are indicated, and recommendations for practical application are given. Conclusion: The results obtained can be used by power grid companies to analyze the state and efficiency of power grids, and may also be of interest to researchers working on the creation of digital twins of power grids.

Resent constructions of road bridges’ expansion joints

At present, there are high requirements for materials and construction elements in civil engineering in common. These intentions are fully applicable to such bridge construction elements as expansion joints. The new developed models are needed, in which all the defects and limitations of the previous models are solved and the maximum of operational life is reached. The main types of bridge expansion joints: closed joints, filled-type joints, covered joints. In this article the construction features, advantages and disadvantages of the listed expansion joints are considered. On the basis of the gotten results it is seen that new and developed models of different types expansion joints have better rates in all of considered criteria. It means that these joints have bigger structural reliability and provide longer operational life of the construction. The most effective models of bridge expansion joints are: closed-type joints with metal support plate, filled-type joints with convex V-shaped compensator and covering slab, covered joints with finger slabs and flap hinged rods and springs.

Calculation, design and manufacture of heteropolar magnetic levitation and linear drive systems of maglev transport

Background: The methods of calculation and elements of the technology for creating heteropolar magnetic systems of levitation, lateral stabilization and a rotor-runner of a traction linear synchronous motor for the development of the transport technology "Russian Maglev" in order to achieve an increased levitation gap of 0.2 m, reduce the threshold speed of the exit vehicle in levitation mode up to 10 km/h. Aim: to develop methods for calculating and designing heteropolar poles from elementary permanent magnets, coils of the same type based on composite low-temperature superconductors and high-temperature tape superconductors of the second generation and a step-by-step technology for their production. Tasks: Creation of an on-board magnetic system of levitation and lateral stabilization, allowing to provide a levitation gap of 0.2 m, a threshold value of vehicle speed of 10 km/h when transition to levitation mode, to reduce stray magnetic fields to the level of the natural field of terrestrial magnetism of 50 T; Creation of a rotor-runner of a linear synchronous motor with an ironless stator with a power of 10 MW. Methods: outlines the main calculation methodologies: "analysis" and "synthesis". The "analysis" methodology is adopted in solving the "direct" calculation problem, when the configuration of the magnetic system is set and the magnetic field in the working area is calculated, and, if necessary, the stray magnetic fields. This methodology can be effectively applied if there is experience in creating magnetic systems. Otherwise, the "synthesis" methodology is applied, which is used in solving the "inverse" calculation problem, in which the picture of the distribution of the magnetic field in the working zone is set and the configuration of the magnetic system is found (synthesized). Results of the study performed: The parameters and characteristics of high-energy permanent magnets made of rare-earth metals, low-temperature and high-temperature superconducting winding materials have been analyzed, the choice of permanent magnets and superconducting winding material has been made; Calculations of the magnetic system of permanent magnets in the "Halbach assembly" and in the traditional assembly in a toothed ferromagnetic core have been carried out; Calculations of a track coil with a rectangular cross-section of the winding are performed; Methods for calculating and optimizing superconducting magnetic systems from a set of similar track modules have been developed; Conclusions: The results of the performed fundamental research will allow starting the calculation, design and construction of conveyor-main passenger and freight lines of maglev transport, as well as urban public transport.

Starting forces of the traction linear induction motor with adjustable resistance of the short-circuited winding of the secondary element

Background: Development and research of linear traction drives for Maglev transport is an urgent task. Linear induction motors can be used as traction machines for advanced rolling stock. Aim: Study of the starting characteristics of an adjustable traction linear induction motor with variable resistance by a short-circuited winding of the secondary element. Methods: Theoretically, relations were obtained for calculating the traction starting forces of an adjustable linear induction motor with various designs of a short-circuited winding of the secondary element. Results: Based on the obtained ratios, the calculations of the starting traction forces of linear induction motors intended for use in promising modes of transport were performed. Conclusion: The results of calculating the starting traction forces of adjustable linear induction motors make it possible to reasonably select the modes of starting the motor depending on the design of the secondary winding.

Choosing the best solutions for multimodal oil transportation

Background: to organize multimodal transportation and choose the best route option for fuel delivery, it is necessary to develop an algorithm for choosing the best solution from the considered ones. This is indicated in the Strategy of scientific and Technological Development of the Russian Railways Holding Company for the period up to 2025 and for the future of 2030 ("White Paper", where on pages 25-26 it is said about the need to develop new transport and logistics products and services in global transport chains in the development of multimodal transport and the need to develop and organize new multimodal freight transport). Federal Railway Administrations of the United States, page 127 of the White Paper, points to the need to improve the methodology of integrated multimodal transport planning at the global, national and regional levels, increase the demand for transport and logistics services, and transition to supply chain management. Aim: to develop a method for multi-criteria rationalization of the choice of multimodal transport routes with the possibility of considering hypothetical options. Materials and Methods: the fundamental works of leading scientists in the field of improving the efficiency of production in accordance with the needs of the economy in transportation A.V. Annenkov, P.B. Romanova were used. In the field of justification of decisions on cargo terminals, determining the volume of tank farms with the possibility of their expansion O.B. Malikov, V.N. Sapronov. The application of multi-criteria rationalization by comparing the criteria under consideration is given in the work of A.T. Osminin, which developed a scientifically based method aimed at creating analytical and control systems. In the field of risk analysis and assessment of the work of A.G. Kotenko. The works of A.Y. Akhriev, A.B. Egorov, A.A. Kalushin, V.N. Mirushkin, E.V. Pasyunin, and A.V. Savelyev were studied in the field of improving the optimization of the oil transshipment complex, and the works of M.A. Nazarov and O.M. Sergeeva in the segment of logistics of river and sea oil transportation. Results: it consists in improving the quality of solutions to problems in the transportation of liquid fuel by means of transport in multimodal communication based on the use of the developed method. The set of criteria considered in the method allows you to set and solve transport problems with almost no restrictions on complexity, which in each case allows you to get better results. Conclusion: Using the method in practice allows not only to objectively find the best solution from the considered ones, but also to study hypothetical transportation schemes with the possible construction of new tracks and their elements, and compare existing and new schemes by a set of criteria, including construction costs and payback time of new tracks, and as a result find the best solution to the task.

Switched reluctance traction motor with improved indicators of the reliability of bearing units for an electric rolling stoсk

Aim: Establishment of preconditions for the introduction of a switched reluctance motor into the system of traction drive of an electric rolling stock by improving the performance of the bearing unit. Methods: Calculations were carried out using the finite element method. Results: It was found that the calculated values ​​of force of a one-way magnetic attraction applied to the bearing unit are tens of times higher than the permissible values. The result is accelerated wear and failure of the bearings. An algorithm is proposed which takes into account the influence of one-way magnetic attraction forces in an uneven air gap. Conclusion: The algorithm makes it possible to change the production cycle and improve the consumer quality of the switched reluctance traction motor.

Analysis of the application of electric conducting concrete in the power industry

At present, on the territory of the Russian Federation, there is no massive use of electrically conductive reinforced concrete structures in the electric power industry due to insufficient operating experience and a low rate of research on electrically conductive concretes. The article compares the main characteristics of existing electrically conductive concrete. The paper shows the disadvantages of traditional concrete and existing electrically conductive concrete. The electrically conductive concrete was selected, the most suitable for further research, testing and direct modernization of the composition based on the results obtained. The main disadvantages of existing electrically conductive concretes are the high cost and specificity of electrically conductive components and other additives, as a consequence of the amount of capital investment in mass and large-scale production, as well as the lack of operating experience as overhead supports.

Modern technological and innovative solutions aimed at increasing the flow and transportation capacities of railway directions

In the modern period, the railway industry faces the challenges of both intensifying the use of existing lines and developing new high-speed transport systems. The lack of capacity reserves for railway lines leads to the abandonment of freight trains, which in turn complicate the management of train traffic. Existing ways to increase throughput are divided into organizational and technical and reconstructive. Historically, the development of railway automation systems has contributed to changing the system of organizing train traffic, increasing the capacity of railway sections. The paper considers various technological and innovative solutions aimed at increasing the capacity and carrying capacity of railway lines, including an assessment of the effectiveness of using mobile block sections and virtual couplings in conditions of limited capacity of railway directions. To solve the problem of increasing the throughput of the investigated cargo-intensive direction of Kotelnikovo-Tikhoretskaya-Razezd 9 km of the North Caucasian Railway (NKR), the method of calculating the throughput was used, as a result of which options for its increase on the cargo-intensive section were proposed, ensuring high reliability of transportation, timely delivery and unloading cargo.

Methodology for assessing the readiness of territories for the formation of the infrastructure of the innovative port logistics complex

The article analyzes the existing methods for assessing the readiness of territories for the formation of a logistics complex, examines the factors affecting the formation of the infrastructure of an innovative port logistics complex. An author's method for assessing the readiness of territories for the formation of the infrastructure of an innovative port logistics complex.