scholarly journals DETERMINATION OF THE TECHNICAL CONDITION OF A RAILWAY BRIDGE

2020 ◽  
pp. 32-39
Author(s):  
I. Seryh ◽  
E. Chernyshova ◽  
A. Degtyar
Keyword(s):  
Technical Condition ◽  
Operating Conditions ◽  
Industrial Safety ◽  
Normal Operation ◽  
Bridge Structure ◽  
Structural Elements ◽  
Railway Bridge ◽  
Technical Examination ◽  
Second Category

The reliability and durability of any structures, including in transportation, depend on operating conditions and on timely diagnostics of damages and defects arising during their normal operation. Proper diagnostics will allow to determine the degree of wear of the structures, as well as to identify causes of damages. This work will focus on industrial safety inspection, using railway bridge built in 1987 as an example. A comprehensive inspection included full technical examination of the bridge and all its structural elements. The outcome and all necessary repair recommendations are documented. Recommendations for reconstruction and restoration methods of the damaged elements and structures of the bridge are based on a scientifically accurate assessment of its technical condition to establish signs and causes of the damages. Based on the results of the comprehensive inspection of all the damages in the bridge structure, the technical condition of the bridge is assessed three points on a five-point scale. The identified failures in durability and safety are classified in the second category. The categories of defects found are mainly related to safety - B1, B2, durability - D2, D3, and repairability - P2, Р3.

scholarly journals Nalysis of Changes to Steel Footbridge Geometry Within 25 Years in Service

2018 ◽  
Vol 28 (2) ◽  
pp. 164-176
Author(s):  
Jacek Sztubecki ◽  
Adam Bujarkiewic ◽  
Justyna Sobczak-Piąstka ◽  
Tomasz Janiak ◽  
Jarosław Gajewski
Keyword(s):  
Service Life ◽  
Technical Condition ◽  
Frame Of Reference ◽  
General Analysis ◽  
Bridge Structure ◽  
Structural Elements ◽  
Bridge Structures ◽  
Special Value ◽  
Static Operation

Abstract Identification of the technical condition of bridge structures should be supplemented by determination of structural displacements in relation to the adopted frame of reference and measurement of changes to the geometry of its individual elements. Of special value are the results of measurements of the same values obtained along an extended service life. They provide an opportunity to compare results, track down tendencies, and more quickly recognise signs of aggravating technical condition of structures. The paper presents an analysis of changes to the geometry of a bridge structure – a cable– stayed footbridge used for pedestrian and bicycle traffic across the Brda river in Bydgoszcz. Measurements were made by means of surveying techniques within a period of 25 years of the structure service life. The collected data enabled numerous comparative analyses to be conducted. Displacements of footbridge structural elements observed across time led to formulation of recommendations for further use of the footbridge. For instance, recommendations for footbridge adjustment, including improvement of its geometry, were provided. In addition, a general analysis of the effect of footbridge displacements on its static operation was conducted.

An Extended Model of Light Railway System Used in Analysis of Normal Operation and Fault Conditions

2014 ◽  
Author(s):  
Sorin Deleanu ◽  
Keith Forman ◽  
David C. Carpenter ◽  
Calin Munteanu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Short Circuit ◽  
Operating Conditions ◽  
Normal Operation ◽  
Dc Power ◽  
Railway System ◽  
Analytical Approaches ◽  
Element Method

The paper provides a description of the analysis of a Light Railway System for two configurations: - Rails above the ground and catenary supply - Track in a tunnel and power rail supply. Finite Element Method (FEM) analysis is compared to classical analytical approaches by Carson, Pollaczek, Bickford and Tylavsky. Reviews of methods to determine self and mutual impedance for electrified railroads are provided. The solution of finite element method (FEM) applied for the determination of impedance for the two traction rail and catenary configuration, modeled and examined, consists of computational analysis based upon minimizing the energy of electromagnetic field. The analytic impedance models are built on Carson-Pollaczek–Bickford equations, adjusted by Tylavsky, for two situations: when the ground is perfectly insulated and when considering the earth return current. The railway track – catenary is integrated in a system containing the model for traction substation(s) with DC power output and moving vehicle with induction motors, controlled using voltage inverters with pulse width modulation. The light transit train, supplied with a rectified DC power, is subjected to a significant harmonic content, which may affect the signal and control circuits. It is then shown that the power and signaling characteristics of the modelled system can predict the magnitude of the perturbation current for different frequencies, in normal operating conditions and in presence of faults as well. In many of the light transportation systems, from all types of faults, the DC short-circuit at the output of the power rectifiers used for energizing the power rail and/or catenary presents a special interest. This is because of two main reasons: the positions of the vehicle-loads are in continuous changing and, even if they operate from DC sources, the parent network is still of AC type. A key issue was the determination of the distributed parameters (resistances, inductances) of the running track and catenary, from experimental data and preliminary analytical and numerical calculations, followed by the analysis of their dependencies with the current magnitude and frequency response. A specific short-circuit study case is simulated when using a model of the traction system for the purpose of the DC fault current prediction. The paper concludes with a discussion of future developments and further work.

scholarly journals Visualization and diagnostics of reliability of the object with changing the functioning conditions

2021 ◽  
Vol 263 ◽  
pp. 02009
Author(s):  
Evgeny Gvozdev
Keyword(s):  
Technological Process ◽  
Safety Margin ◽  
Operating Conditions ◽  
Hazardous Substances ◽  
Structural Elements ◽  
Base Materials ◽  
Reliability Indicator ◽  
Margin Of Safety ◽  
Fire And Explosion

The object of the scientific research is buildings (structures), which requiring the determination of a reliability indicator for their further operation in new operating conditions, the determination of additional loads in the form of (explosions, fires, vibration processes). The solution to such problems is relevant for buildings (structures), which are acquired (leased) by the owner, for their further operation in the new conditions of the technological process associated with the handling, storage, processing and production of fire and explosion hazardous substances (materials). It is important to determine the readiness of buildings (structures) for operation in the new conditions of functioning of the technological process of production, it is proposed to use deterministic, statistical and probabilistic approaches. It is proposed to use a simplified assessment of the safety margin of a building (structure) by yield strengths (for steel elements) and strength (for base materials, load-bearing walls, partitions and ceilings) corresponding to the maximum allowable values for their destruction. The innovative approach is described that allows us to solve the problems of assessing the strength reliability of structural elements of buildings (structures) to obtain guaranteed characteristics of a given margin of safety, its resistance to possible realized effects (explosions, fires, vibration processes)

scholarly journals THE ALGORITHM OF COMPLEX DIAGNOSTICS OF TECHNICAL CONDITION OF BUILDING STRUCTURES ON THERMOGRAMS ANALYSIS

2020 ◽  
pp. 23-28
Author(s):  
D. Karpov
Keyword(s):  
Construction Projects ◽  
Thermal Power ◽  
Technical Condition ◽  
Building Structures ◽  
Structural Elements ◽  
Highly Qualified ◽  
Energy Survey ◽  
Measurement Base ◽  
Actual Mass

the algorithm of complex diagnostics of a technical condition of building constructions and structures on the analysis of thermograms is offered. An attempt is made to systematize and logically build a sequence of stages of energy inspection of heat-consuming and heat-generating construction projects and their structural elements. The presented algorithm includes the main stages performed in such surveys. It differs from the known technologies of energy monitoring of buildings and structures by the presence of two additional stages, which are an integral part of any energy survey: determination of the relative surface humidity of building structures and the actual mass flow of coolant through the heating device for the analysis of thermal images. The implementation of energy (thermal imaging) and technical inspections according to the presented structural scheme requires not only the presence of appropriate instrumentation and measurement base, but also the involvement of highly qualified specialists (civil engineers, thermal power engineers, thermal physicists, operators-thermographers, etc.).

scholarly journals DETERMINATION OF TECHNICAL CONDITION OF BUILDING CONSTRUCTIONS BASED ON COMPREHENSIVE ASSESSMENT OF BUILDING PRODUCTION

2019 ◽  
pp. 22-27
Author(s):  
А. Малахов ◽  
A. Malahov ◽  
В. Косинов ◽  
Viktor Kosinov
Keyword(s):  
Technical Condition ◽  
Comprehensive Assessment ◽  
Structural Elements ◽  
Industrial Facilities ◽  
Engineering Research ◽  
Industrial Buildings ◽  
Metal Frame ◽  
Capital Construction ◽  
Instrumental Control

The article deals with the issues related to the assessment of the technical condition of structural elements, taking into account the stages of engineering research, design and installation. The importance of the topic under consideration is due to a large number of accidents at civil and industrial facilities that occur before the exhaustion of the bearing capacity. The analysis of the object (the metal frame of industrial buildings) is carried out on the basis of project documentation, data obtained by a full-scale survey, visual and instrumental control, numerical methods of research. The qualitative and quantitative parameters of the capital construction object necessary for assessing the technical condition are presented. They include design schemes of frame structures, materials, their characteristics, defects and parameters. The study shows the importance of comprehensive assessment of capital construction facilities in terms of constructive safety. Identification of errors at each stage of construction allows to prevent emergencies that lead to the destruction of the load-bearing system and to develop measures to establish the possibility (impossibility) of repair or reconstruction

scholarly journals MODEL FOR DETERMINATION OF CHARACTERISTICS OF RAILWAY TRAIN REGIME MAPS

2020 ◽  
pp. 132-142
Author(s):  
A. Falendysh ◽  
A. Gatchenko ◽  
O. Kletska ◽  
E. Kiritseva ◽  
M. Barybin
Keyword(s):  
Energy Efficient ◽  
Mechanical Energy ◽  
Technical Condition ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Railway Transport ◽  
Ecological Requirements ◽  
Methods Of Calculation ◽  
Methods Of Operation

The article considers the issues of determining rational approaches to the creation of train maps, the rational use of diesel modes and the use of automated computer simulation system. Based on the obtained results, an energy-efficient mode of train driving is proposed and a mathematical model of the locomotive operation character is created. There is a need to review obsolete regime and train locomotive crews in the latest methods of operation. The basic values and methods of calculation for specific operating conditions on the basis of the law of conservation of mechanical energy are established. It is proposed to create a passport of each locomotive to determine the rational weight norms on the existing service shoulders. After all, overloading or underutilization of the locomotive's resource is associated with loss of profit or the emergence of emergencies. The necessity of the offered methods within the limits of ecological requirements to traction rolling stock is proved. The possibility of forming a rational system of mileage between technical inspections and repairs for each locomotive as a whole on the basis of forecasting and statistics is determined. It is recommended to further implement mathematical modeling and digital means of monitoring the technical condition after repairs to achieve economic efficiency of railway transport.

scholarly journals Determination of cracking causes in building structural elements

2021 ◽  
Vol 258 ◽  
pp. 09038
Author(s):  
Valentina Halushko ◽  
Alexandr Meneiliuk ◽  
Stanislav Kyryliuk
Keyword(s):  
Residential Buildings ◽  
Residential Building ◽  
Normal Operation ◽  
Theoretical Problem ◽  
Structural Elements ◽  
Regulatory Requirements ◽  
Different Depths ◽  
Base Soil ◽  
Horizontal Displacements

The article deals with the problems of buildings built many years ago, in which current and major repairs were not carried out in an appropriate manner. At the same time, buildings experience various deformations, such as yield, heel, subsidence, deflections, bends, twists, distortions, horizontal displacements. The survey of residential buildings built in the 80s is described and the analysis of the results of the survey of one of these buildings is carried out. The theoretical problem of the distribution of moisture in depth and various degrees of soil moisture has been solved. The reasons for the appearance of cracks in structures and cracks between individual building elements are also determined. The survey of a 9-storey brick residential building, built in the late 80s, which is in the period of normal operation, is considered. At the same time, the considered building is operated with significant deviations from regulatory requirements. The causes of cracks in individual structures and cracks between individual elements in the building are found. The problem of the distribution of moisture in depth with local soaking is solved on the basis of a numerical method, and the character of soil moistening at different depths with different degrees of moistening and characteristics of the base soil is obtained.

IMPROVING THE ACCURACY OF DETERMINING THE FREQUENCY

2021 ◽  
Vol 73 (2) ◽  
pp. 23-31
Author(s):  
L.O. SAVIN ◽  
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Road Transport ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Optimal Frequency ◽  
Average Operating

The paper substantiates a method for increasing the accuracy of determining the optimal fre-quency of maintenance of one of the most important units of automotive equipment operating in various climatic and road transport conditions - its engines, and also presents circuit proposals for the implementation of this method. The proposed approach makes it possible to significantly increase the accuracy of determining the optimal frequency of maintenance of internal combustion engines by taking into account their real technical condition when operating in different (different from the average) operating conditions. The article provides typical examples of calculating the determination of the optimal frequency of maintenance of automotive equipment, and also estimates the gain achieved when using the approach proposed in the work.

scholarly journals Methodology remaining lifetime determination of the building structures

2018 ◽  
Vol 230 ◽  
pp. 02023 ◽  
Author(s):  
Yuriy Otrosh ◽  
Andrii Kovalov ◽  
Oleg Semkiv ◽  
Irina Rudeshko ◽  
Valentin Diven
Keyword(s):  
Structural Damage ◽  
Residual Life ◽  
Technical Condition ◽  
Building Structures ◽  
Design Elements ◽  
Fixed Assets ◽  
Technical Examination ◽  
Effective Use ◽  
Technical Solutions

The paper proposes an approach to determining the increase of the normative lifetime of building structures on the basis of the algorithm of numerical calculation of the residual life of structures, which is performed on the basis of the results of defining parameters obtained during the technical examination and evaluation of defects, failures and structural damage. To calculate the structures, the simulation of the stressstrain state of the building structures with the involvement of OK LIRA was used. Simulation allowed performing optimization of technical solutions and strengthening of structures for buildings. The methodology is used to design elements for strengthening the structures of buildings and structures. Reliable estimation and forecasting of the technical condition enables to prevent the occurrence of accidents of structures and their associated losses, to use rational use of funds for current and capital repairs, and to regulate the technical condition in such a way as to achieve the most effective use of fixed assets.

scholarly journals Development of Devices for the System of Monitoring the Strength Features of Concrete in Operated Buildings and Structures Based on the Ultrasonic Pulse Method

2019 ◽  
pp. 22-27
Author(s):  
Ya. Serikov
Keyword(s):  
Building Materials ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Technical Condition ◽  
Structural Elements ◽  
Survey Results ◽  
Static And Dynamic Loads ◽  
Object Material ◽  
Negative Factors

  Operation of buildings and structures for various purposes is accompanied by an impact on their structural elements, building materials, and a complex of negative factors. These factors include the lifespan, climatic parameters, static and dynamic loads, dustiness, air pollution, etc. Their action worsens the physico-mechanical characteristics, the structure of concrete. This reduces the reliability of structural elements, reduces the life of the construction object. In DBN V. 1.2-14-2009 «The system of ensuring the reliability and safety of construction objects» set the classification of construction objects by classes of consequences in the event of an accident. The estimated lifetimes of each type of construction objects are also determined. Extension of life is allowed only after inspection and evaluation of the technical condition of the construction object, material characteristics, through the determination of the degree of their compliance with regulatory requirements. The importance of obtaining reliable survey results requires the improvement of relevant instruments and metrology. The described developed system of monitoring of construction objects, as well as instrumentation and system based on the ultrasonic pulse method. They are designed to control the physico-mecha-nical characteristics, the structure of concrete and other building materials. The developed devices and system are characterized by increased accuracy, reliability and reliability of measurements.

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