scholarly journals Risk-Based Approach in Assessing the Technical Condition of Foundations of Bridge Structures

2021 ◽  
Vol 18 (6) ◽  
pp. 64-73
Author(s):  
E. V. Kaimov
Keyword(s):  
Mathematical Model ◽  
Technical Condition ◽  
Technical State ◽  
Probabilistic Methods ◽  
Transport Infrastructure ◽  
Practical Significance ◽  
Structural Elements ◽  
Functional Quality ◽  
Bridge Structures

The objective of this article is to consider the use of predictive mathematical models for assessing risks associated with a critical loss of values of functional quality of bearing structural elements (foundations) of bridge structures using methods of probabilistic analysis and forecasting the risks of reducing of values of indicators of the technical state of structural elements.The research results in development of an algorithm and a mathematical model that characterise the features of the process of reducing of values of indicators of the technical condition of load-bearing structures during the service life cycle. The results of assessing the loss of functional quality of foundations obtained using this model are presented.The practical significance of the study relates to the possibility and expediency of using probabilistic methods for predictive assessment of the technical state of loadbearing structures. With the help of an appropriate mathematical model, it becomes possible to proceed with design rationale of indicators of functional quality of foundations of bridge structures.The need to improve regulatory provisions for design and forecasting of indicators of the technical condition of transport infrastructure objects is substantiated.

Probabilistic Analysis of Intermediate Floor Steel and Wooden Structures in the Old Urban Development Building

2014 ◽  
Vol 633-634 ◽  
pp. 1140-1147
Author(s):  
Vladimir Alekseevich Sokolov
Keyword(s):  
Information Theory ◽  
Urban Development ◽  
Probabilistic Analysis ◽  
Technical Condition ◽  
Probabilistic Methods ◽  
Technical Diagnostics ◽  
Structural Elements ◽  
Complex Technical Systems ◽  
Technical Systems ◽  
Wooden Structures

The article suggests an approach to determine structural elements technical condition, based on the mathematical probabilistic apparatus of technical diagnostics. Diagnostics are performed using probabilistic methods of complex technical systems conditions recognition. Probabilistic parameters are calculated according to Bayes’s rule. The paper shows a diagnostics example of intermediate floor elements and systems in the old urban development building. Both the suggested method and information theory methods are used during diagnostics.

scholarly journals PROSPECTS OF SOCIAL INFRASTRUCTURE DEVELOPMENT ON THE EXAMPLE OF DNIPROPETROVSK REGION

2021 ◽  
Author(s):  
Yuliia Goley
Keyword(s):  
Sustainable Development ◽  
Technical Condition ◽  
Transport Infrastructure ◽  
Educational Institutions ◽  
Infrastructure Development ◽  
Social Infrastructure ◽  
Wide Range ◽  
Social Environmental ◽  
High Level

A global imperative that is especially relevant for Ukraine in view of the social, environmental and economic challenges of sustainable development is to ensure sustainable development. Therefore, addressing the topic of prospects for the development of infrastructure in the country's regions, given the fact that Ukraine is currently moving towards the implementation of a wide range of reforms aimed at improving the welfare of the population is a very important topic. First, because the components of the infrastructure are the main principles of quality of life, which affect the level of satisfaction of citizens. Secondly, a highly developed infrastructure complex is able to bring the country to a whole new European level of development. In terms of infrastructure development, the following priority areas are: housing and communal services, transport and communications, medicine, education, recreation system, ecology, social security, culture, as the most important systems that ensure the gradual sustainable development of each region, and the country as a whole. Despite the sufficient attention of state and regional authorities to the development of infrastructure in many regions of the country, there are still problems of existing infrastructure facilities, such as - educational, cultural, sports, medical, preschool educational institutions and schools, hospitals, etc. The degree of wear of which sometimes reaches 60%. In addition, there are problems with the provision of urban and regional transport to meet the existing needs of residents of the city and its remote areas, which provokes significant time to travel, and so on. In general, the quality of most social infrastructure facilities leaves much to be desired, which determines the high degree of relevance of the topic of this article. The article analyzes the current state of educational institutions, health care and transport infrastructure of the Dnipropetrovsk region, identifies urgent problems. In addition, the problems of the development of transport infrastructure (insufficient number of transport units, its unsatisfactory technical condition, frequent breakdowns, high level of wear, etc.) are highlighted, which requires taking measures to increase the level of accessibility and comfort of transport in the region.

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.

scholarly journals THE MODEL FOR EVALUATING THE CRITERIA DESCRIBING THE QUALITY OF THE TRIP BY INTERNATIONAL TRAIN

2014 ◽  
Vol 20 (3) ◽  
pp. 484-506 ◽  
Author(s):  
Lijana Maskeliūnaitė ◽  
Henrikas Sivilevičius
Keyword(s):  
Mathematical Model ◽  
Quantitative Estimate ◽  
Quality Index ◽  
Additive Model ◽  
Technical State ◽  
Railway Track ◽  
Suggested Model ◽  
The Real ◽  
Real Value

The quality of multifaceted objects or phenomena can be hardly described or evaluated by a single criterion. The quality of the trip by train is described by a set of quantitative and qualitative criteria. The influence of all the criteria on the trip by international train may be evaluated by a comprehensive quality index (CQI) or quality index K. An additive model is offered for calculating CQI, which consists of the average weights of the criterion groups, as well as normalized weights and variables of the criteria, showing the correspondence of the real value of each criterion to the best, critical or allowable value. A mathematical model, which may be used for determining the quality of the trip by train based on the criteria describing the elements of the train and technical state of the railway track is also presented. Based on the use of 16 criteria describing the elements of the train and the parameters and the technical state of the railway track, the quantitative estimate KA (multiple criteria index) is obtained. The suggested model and the techniques used in the work may be applied to determining the quality or effectiveness of other objects or processes, which can be described by sets of criteria.

scholarly journals ANALYTICAL ESTIMATION OF THE TECHNICAL CONDITION OF PLUNGER PAIR WHEN COMPLETED BY HYDRODENSITY

2018 ◽  
Vol 13 (1) ◽  
pp. 138-142 ◽  
Author(s):  
Юрий Казаков ◽  
Yuriy Kazakov ◽  
Владимир Иванов ◽  
Vladimir Ivanov
Keyword(s):  
Mathematical Model ◽  
Technical Condition ◽  
Technical State ◽  
Plunger Pair ◽  
Factors Influencing ◽  
Analytical Estimation

The paper considers the factors influencing the estimated indicator of the technical state of the plunger pairs, when they are equipped according to the hydrodensity. To determine the influence of factors on the estimated value of the plunger pair in terms of hydrodensity, a two-factor experiment was planned and implemented, and a mathematical model was obtained for the process of selecting plunger pairs as a set for hydro-densities. On the basis of the research, it is suggested to complete the plunger pairs as a set on the KI-759 device with a mathematical dependence to reduce the error.

scholarly journals Алгоритм классификации технического состояния топливного регулятора в пространстве параметров рабочего процесса

2021 ◽  
pp. 158-169
Author(s):  
Игорь Валериевич Оганян ◽  
Сергей Валериевич Епифанов
Keyword(s):  
Mathematical Model ◽  
Quality Criterion ◽  
Diagnostic Algorithm ◽  
Test Sample ◽  
Classification Algorithm ◽  
The State ◽  
Technical State ◽  
Working Process ◽  
The Mathematical Model

This article solves the problem of constructing an algorithm for classifying the technical state of the fuel regulator of a turboshaft engine of a helicopter in the parameter space of the regulator's working process and obtaining estimates of the state of the investigated product. In the introduction to this work, the main methods of classifying the technical state are considered, and a brief justification for the choice of the method for classifying the state of the product in the space of measured parameters used to construct the algorithm is considered in this article, is given. The criteria for the presence of a malfunction in the investigated controller are determined and the basic requirements for the classification algorithm are formed. To simplify the problem being solved, many assumptions about the diagnosed defects were made. The article provides descriptions of all components of the classification algorithm. A brief description of the mathematical model of the fuel regulator is given. The operating mode of the regulator for analysis is selected, and the list of state parameters required for diagnostics and the list of diagnostic parameters of the working process is given. The technique of linearization of the mathematical model of the controller and the technique of constructing the matrix of influence coefficients, which is the basic element of the entire algorithm, is described. The probabilistic characteristic of the credibility of the classification algorithm is determined, and the derivation of the formula for its calculation, based on the Bayes theorem, is also given. To assess the quality of the classification by the diagnostic algorithm, a test sample of workflow parameters was formed. The methodology for constructing a test sample is described and its size is determined. After the product condition estimates are obtained according to the test sample data by the classification algorithm, such a quality criterion as the recall is calculated. As a result of assessing the recall, a table was formed with the values of this criterion for each class. The recall of the algorithm on average for all defects was 89 %. The conclusions indicate possible methods for improving the quality of diagnosis by the algorithm.

scholarly journals Analysis of the technical condition of a railway bridge at risk of failure

2019 ◽  
Vol 284 ◽  
pp. 01005
Author(s):  
Mieczysław Piechota ◽  
Grzegorz Rogojsz
Keyword(s):  
Load Capacity ◽  
Degradation Process ◽  
Technical Condition ◽  
Steel Bridge ◽  
Bridge Structure ◽  
Railway Bridge ◽  
Railway Bridges ◽  
Actual Load ◽  
Bridge Structures

The paper presents an analysis of the technical condition of a railway bridge structure with a span structure in the form of welded girders. Static diagram of the structure consists of two simply supported beams. The theoretical span of the spans is 2 x 14.50 m, their overall length is 14.90 m, and the total length of the crossing is 30.6 m. The reasons for the formation and development of bridge degradation were analysed. In addition, the actual load capacity of the structure was determined and the possibility of its further operation was evaluated. Particular attention was given to the quality of workmanship and the degradation progress of welded joints, which led to the exclusion of the object from use. The main purpose of the presented analyses is to formulate general recommendations, whose implementation in a direct or indirect form may contribute to reducing the degradation process of railway steel bridge structures. When inspecting welded railway bridges, particular attention should be paid to the condition of welds and to control and prevent the structure from cracking.

scholarly journals Semi-Markov analytical model for assessing the quality of the maintenance system and the state of electromechanical complexes

2020 ◽  
Vol 2 (127) ◽  
pp. 15-24
Author(s):  
Volodymyr Kazhan ◽  
Vasyl Stopkin ◽  
Ksenia Kotlyarova ◽  
Alexander Yudin
Keyword(s):  
Mathematical Model ◽  
Analytical Formula ◽  
Technical Condition ◽  
Technical State ◽  
Analytical Relationship ◽  
Maintenance And Repair ◽  
Main Research ◽  
Availability Factor ◽  
Operation Process ◽  
Optimal Maintenance

Analysis of basic research. In practice, the EMC reliability indicators, in particular the failure rate, are time-varying quantities. In view of this, it is necessary to determine such periodicity values and maintenance volumes that would ensure the EMC maximum availability factor. The most adequate mathematical model for analyzing the technical state of EMC can be obtained using the apparatus of the theory of semi-Markov processes (PMF), the basis of which is an oriented graph of the basic states and transitions (GSP) of EMC during operation, which allows to formulate maintenance and maintenance strategies, the content of a separate strategy is determined a specific set of options for all states of EMC.The purpose of the article. Construction and study of a mathematical model of the EMC operation process to determine the optimal intervals and maintenance and repair strategies.The main research material. The solution to the first problem includes: building a model for the operation of the EMC; the derivation of the calculated ratio for the availability factor as a function of the technical condition of the EMC and the service station; obtaining an analytical formula for calculating optimal maintenance intervals.The paper proposes a combination of indicators ranked by importance in the linear programming problem, where the transfer time, which is a function of the SRT parameters and the technical condition of the EMC, is selected as the objective function, and the remaining indicators (readiness level, complex operation costs, and others) are taken into account in the form of restrictions. The result of solving this problem is a set of maintenance and repair options at each step of the operation of the EMC, which comprise the content of the optimal maintenance and repair strategy.Conclusions. An analytical relationship was obtained on the basis of the semi-Markov model of the operation process that allows one to calculate the optimal conditions for ensuring the availability factor of the periodicity of maintenance, which makes it possible to control the unsteady operation of the EMC, to obtain the necessary technical and economic quality indicators to build an adaptive ACS with the technical state of the EMC.

scholarly journals Economic and Mathematical Modeling of the Quality of Services Provided by the Urban Passenger Transport Infrastructure Us-ing Nonfinancial Indicators

2018 ◽  
Vol 7 (4.38) ◽  
pp. 452
Author(s):  
Vladimir Sekerin ◽  
Mikhail Dudin ◽  
Dmitri Shevchenko ◽  
Konstantin Zadornov ◽  
Diana Maleeva
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Transport Infrastructure ◽  
Quality Of Services ◽  
Financial Indicators ◽  
Queuing Systems ◽  
Passenger Transport ◽  
Passenger Transportation ◽  
Main Factors

The article reviews the issues of justifying the expediency of using financial indicators to assess the quality of passenger transportation and identification of the main factors that influence the quality of transportation. An economic and mathematical model of the passenger transportation quality using nonfinancial indicators was developed in the study.It was proposed to use a mathematical toolkit of the theory of queuing systems (QS) to study the operation of the route of the urban passenger transport system (UPTS).  

scholarly journals IMPROVING THE QUALITY OF TRANSPORT SERVICES FOR LONG-DISTANCE ROAD PASSENGER TRANSPORTATION

2017 ◽  
Vol 11 (6) ◽  
pp. 54-66
Author(s):  
Наталья Москалева ◽  
Natal'ya Moskaleva
Keyword(s):  
Social Services ◽  
Technical Condition ◽  
Practical Significance ◽  
Insurance Companies ◽  
Negative Consequences ◽  
Road Transportation ◽  
Long Distance ◽  
Travel Agents ◽  
Transport Services

The article justifies the role of self-control by transportation organizations and monitoring by tour operators and insurance companies of the behavior of drivers, their health and technical condition of vehicles. The article reveals the methodology of improving the quality of social services for the public by monitoring the behavior, health of drivers of vehicles and the technical state of vehicles in longdistance, international transport of the population (including tourists). The methodology is aimed at identifying possible dangers, discomfort in the process of providing services to the population and proactive purposeful actions to eliminate or minimize the negative consequences. The methodology contains a set of measures and recommendations that improve the quality of tourism road transportation, and allow car carriers, tour operators and travel agents significantly to reduce financial costs by avoiding traffic accidents through the fault of drivers of car carriers. The author develops and analyzes the concepts of behavior, the health status of drivers of the vehicle, the signs of their manifestation. The methodology includes recommendations for transportation organizations, tour operators (travel agents) for tests of the behavior of vehicle drivers through a «mysterious passenger». The author suggests ways to organize quality control of pre-trip medical examination of drivers. The author recommends for auto carriers introduce measures aimed at maintaining the normal technical condition of vehicles. The practical significance of the study lies in the possibility of implementing the methodology in the work of auto carriers, tour operators, travel agents not only in the Russian Federation, but also the host party abroad.

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