The article presents the theoretical provisions and practical possibilities of regulating the technological process implementation of construction railway track entity using an artificial neural network. Railway construction as a complex dynamic system requires certain resources for its maintenance. Under these conditions, effective control over the technology of work execution performed during the railway track entity construction is of decisive importance. This can be achieved by improving the existing system of engineering and technical support for railway construction through the introduction of a subsystem for engineering and intellectual support of technological processes for the railway entities construction. One of the subsystem’s tasks is the effective use of automation tools with artificial intelligence elements. The appearance of deviations from planned requirements during construction work, due to the stochastic nature of railway construction, leads to technology violations, an increase in labor costs, prime cost, an increase in duration and, as a result, a deterioration in the railway entity operational characteristics. To avoid such a development of events, a prompt review of the adopted technological solutions is necessary. To this end, as part of the methodology formation for technological processes engineering and intellectual support of railway construction, a system has been developed for regulating the technological processes implementation for the railway entity construction. The process regulation is based on the work execution monitoring results. Adjusting the technological process to changing work execution conditions flexibility in the railway track entity construction. This is achieved by choosing regulatory solutions using the artificial neural network capabilities and then adjusting the work progress. Based on the theoretical study results, the article presents the practical aspects of the work execution processes regulation implementation in railway construction using neural network technologies on the example of a flooded railway roadbed subgrade construction. The results presented in the article were obtained in the course of a dissertation research carried out by the author.
{"title":"Regulation of work execution processes in railway construction using neural network technologies","authors":"A. Polyanskiy","doi":"10.15862/03sats223","DOIUrl":"https://doi.org/10.15862/03sats223","url":null,"abstract":"The article presents the theoretical provisions and practical possibilities of regulating the technological process implementation of construction railway track entity using an artificial neural network. Railway construction as a complex dynamic system requires certain resources for its maintenance. Under these conditions, effective control over the technology of work execution performed during the railway track entity construction is of decisive importance. This can be achieved by improving the existing system of engineering and technical support for railway construction through the introduction of a subsystem for engineering and intellectual support of technological processes for the railway entities construction. One of the subsystem’s tasks is the effective use of automation tools with artificial intelligence elements. The appearance of deviations from planned requirements during construction work, due to the stochastic nature of railway construction, leads to technology violations, an increase in labor costs, prime cost, an increase in duration and, as a result, a deterioration in the railway entity operational characteristics. To avoid such a development of events, a prompt review of the adopted technological solutions is necessary. To this end, as part of the methodology formation for technological processes engineering and intellectual support of railway construction, a system has been developed for regulating the technological processes implementation for the railway entity construction. The process regulation is based on the work execution monitoring results. Adjusting the technological process to changing work execution conditions flexibility in the railway track entity construction. This is achieved by choosing regulatory solutions using the artificial neural network capabilities and then adjusting the work progress. Based on the theoretical study results, the article presents the practical aspects of the work execution processes regulation implementation in railway construction using neural network technologies on the example of a flooded railway roadbed subgrade construction. The results presented in the article were obtained in the course of a dissertation research carried out by the author.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article presents a study of the residual fatigue life of superstructures during the introduction of trains with increased axial loads on bridges with riveted superstructures, designed in the fifties of the last century. Unified metal superstructures have been in relatively heavy duty conditions for more than 60 years. During lcontinuous operation, processes occur in elements and joints that lead to the appearance and development of various damages and varying degree failures of hazard, so it is necessary to decide on the further operation of old bridge spans and their replacement. When determining the fatigue life, the linear addition hypothesis of fatigue damage accumulation was used, taking into account the increase in stresses with the introduction of increased axial loads. As a critical measure of damage, providing a given reliability, the value obtained from the calculation results of several hundred cracks in riveted superstructures of older design standards was adopted. The increase in load from the installation of a ballastless bridge floor is taken into account. To determine the residual fatigue life, fatigue data is used depending on the concentration of stresses magnitude in the attachments of the main truss elements. For a more accurate determination of the rivet joints operation stage, the author carried out a wear-out calculation through operation period. The introduction of heavier train loads will lead to an increase in the accumulation of fatigue damage in the elements. If weak rivets in attachments are found during inspection, they must be replaced with high-strength bolts to increase fatigue life. The author obtained that the residual fatigue life of the span structures designed by Transmostproekt has not yet been fully exhausted even with the introduction of heavy trains with a wagon axle load of 27–30 tons.
{"title":"Fatigue life of unified riveted superstructures designed by Transmostproject with the introduction of increased axle loads","authors":"E. Feoktistova","doi":"10.15862/06sats223","DOIUrl":"https://doi.org/10.15862/06sats223","url":null,"abstract":"The article presents a study of the residual fatigue life of superstructures during the introduction of trains with increased axial loads on bridges with riveted superstructures, designed in the fifties of the last century. Unified metal superstructures have been in relatively heavy duty conditions for more than 60 years. During lcontinuous operation, processes occur in elements and joints that lead to the appearance and development of various damages and varying degree failures of hazard, so it is necessary to decide on the further operation of old bridge spans and their replacement. When determining the fatigue life, the linear addition hypothesis of fatigue damage accumulation was used, taking into account the increase in stresses with the introduction of increased axial loads. As a critical measure of damage, providing a given reliability, the value obtained from the calculation results of several hundred cracks in riveted superstructures of older design standards was adopted. The increase in load from the installation of a ballastless bridge floor is taken into account. To determine the residual fatigue life, fatigue data is used depending on the concentration of stresses magnitude in the attachments of the main truss elements. For a more accurate determination of the rivet joints operation stage, the author carried out a wear-out calculation through operation period. The introduction of heavier train loads will lead to an increase in the accumulation of fatigue damage in the elements. If weak rivets in attachments are found during inspection, they must be replaced with high-strength bolts to increase fatigue life. The author obtained that the residual fatigue life of the span structures designed by Transmostproekt has not yet been fully exhausted even with the introduction of heavy trains with a wagon axle load of 27–30 tons.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The work implements the approach formulated by B.V. Deryagin, which states for replacing the Coulomb and molecular (dispersion) forces with a system of tensions obtained on the basis of the mechanics of continuum equations using an incompressible liquid model. Interphasal activity modeling is considered from the standpoint of the equilibrium equations of mechanics of continuum using an incompressible liquid model and representing the interfacial tension tensor as a combination of spherical and deviatoric components. Analytical expressions are obtained for the components of the tension tensor depending on the wetting conditions of a solid surface with a liquid. Intermolecular interaction is determined by the value of the internal pressure of the liquid, which is variable over the interfacial layer thickness. The anisotropy of the interfacial tension tensor in the liquid-solid interfacial layer is expressed by the representation of the spherical and deviatoric components combination, which provides the equilibrium conditions for the interfacial layer. The authors propose to consider the adhesive contact as an external force effect of a solid surface on the volume phase of a liquid, leading to the formation of an interfacial tension tensor with components that are variable over the layer thickness. The authors established the nonlinear nature of the interfacial pressure distribution over the layer thickness, due to the difference in interfacial pressures in the liquid and solid phases in the direct contact zone. It is shown that the surface phenomena specificity is due to the deformation of the liquid volume in the interfacial layer, which leads to a change in intermolecular distances in different directions, which occurs with any kind of force acting on the volume phase of the liquid. The law of intermolecular forces distribution of a liquid depending on the distance is established based on the study results of a sitting drop. Expressions are obtained for determining the long-range interaction radius of liquid molecules and the thickness of the liquid-solid interfacial layer, which give a result that fits into the known estimates of the values of these quantities.
{"title":"Contact interaction model of liquid and solid phases","authors":"Alexey Ignatyev, V. Gotovtsev","doi":"10.15862/11sats223","DOIUrl":"https://doi.org/10.15862/11sats223","url":null,"abstract":"The work implements the approach formulated by B.V. Deryagin, which states for replacing the Coulomb and molecular (dispersion) forces with a system of tensions obtained on the basis of the mechanics of continuum equations using an incompressible liquid model. Interphasal activity modeling is considered from the standpoint of the equilibrium equations of mechanics of continuum using an incompressible liquid model and representing the interfacial tension tensor as a combination of spherical and deviatoric components. Analytical expressions are obtained for the components of the tension tensor depending on the wetting conditions of a solid surface with a liquid. Intermolecular interaction is determined by the value of the internal pressure of the liquid, which is variable over the interfacial layer thickness. The anisotropy of the interfacial tension tensor in the liquid-solid interfacial layer is expressed by the representation of the spherical and deviatoric components combination, which provides the equilibrium conditions for the interfacial layer. The authors propose to consider the adhesive contact as an external force effect of a solid surface on the volume phase of a liquid, leading to the formation of an interfacial tension tensor with components that are variable over the layer thickness. The authors established the nonlinear nature of the interfacial pressure distribution over the layer thickness, due to the difference in interfacial pressures in the liquid and solid phases in the direct contact zone. It is shown that the surface phenomena specificity is due to the deformation of the liquid volume in the interfacial layer, which leads to a change in intermolecular distances in different directions, which occurs with any kind of force acting on the volume phase of the liquid. The law of intermolecular forces distribution of a liquid depending on the distance is established based on the study results of a sitting drop. Expressions are obtained for determining the long-range interaction radius of liquid molecules and the thickness of the liquid-solid interfacial layer, which give a result that fits into the known estimates of the values of these quantities.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article examines the current state and future prospects for the development of the road network in the Russian Federation. It focuses on the implementation of the national project «Safe High-Quality Roads», which aims to achieve new qualitative standards in the construction and operation of the country’s road network. The author analyzes the elements of road maintenance and operation. A comparative analysis is provided, comparing the understanding of road maintenance and operation in the Russian Federation with regulatory documents from the World Bank. The concept of road restoration (rehabilitation) as an allocation criterion by the World Bank is discussed. The study reveals that the domestic approach to selecting repair strategies is based on temporary road operation criteria, while the World Bank’s approach is based on the specific nature of the work and the financial costs associated with repair and road restoration. The author considers various aspects related to repair work on highways. The analysis focuses on groups of factors that contribute to road pavement destruction. External causes, including climatic, geographical, geological, and operational factors that affect road conditions, are identified as the most common causes. Internal causes are also discussed, including outdated technologies, low-quality materials, and errors made during the calculation and construction stages of the road. Different types of pavement destruction leading to complete road damage and the necessity for complete restoration are described and distinguished. Based on this, the article argues that improving quality performance indicators is possible through continuous monitoring of road surface conditions and timely repairs. The author suggests that the use of complex mobile diagnostic laboratories equipped with necessary tools and an information-computing system based on a specialized information-statistical model can significantly reduce the time and financial costs associated with monitoring the condition of roadways. Furthermore, a calculation example is provided to estimate the pavement elasticity index based on traffic intensity and vehicle type. Finally, the article discusses the main initial requirements for justifying road structures.
{"title":"Justification of road structures during the restoration of the disrupted section of the road","authors":"Andrei Tsal","doi":"10.15862/05sats223","DOIUrl":"https://doi.org/10.15862/05sats223","url":null,"abstract":"This article examines the current state and future prospects for the development of the road network in the Russian Federation. It focuses on the implementation of the national project «Safe High-Quality Roads», which aims to achieve new qualitative standards in the construction and operation of the country’s road network. The author analyzes the elements of road maintenance and operation. A comparative analysis is provided, comparing the understanding of road maintenance and operation in the Russian Federation with regulatory documents from the World Bank. The concept of road restoration (rehabilitation) as an allocation criterion by the World Bank is discussed. The study reveals that the domestic approach to selecting repair strategies is based on temporary road operation criteria, while the World Bank’s approach is based on the specific nature of the work and the financial costs associated with repair and road restoration. The author considers various aspects related to repair work on highways. The analysis focuses on groups of factors that contribute to road pavement destruction. External causes, including climatic, geographical, geological, and operational factors that affect road conditions, are identified as the most common causes. Internal causes are also discussed, including outdated technologies, low-quality materials, and errors made during the calculation and construction stages of the road. Different types of pavement destruction leading to complete road damage and the necessity for complete restoration are described and distinguished. Based on this, the article argues that improving quality performance indicators is possible through continuous monitoring of road surface conditions and timely repairs. The author suggests that the use of complex mobile diagnostic laboratories equipped with necessary tools and an information-computing system based on a specialized information-statistical model can significantly reduce the time and financial costs associated with monitoring the condition of roadways. Furthermore, a calculation example is provided to estimate the pavement elasticity index based on traffic intensity and vehicle type. Finally, the article discusses the main initial requirements for justifying road structures.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The submerged floating tunnel (also SFT from the English Submerged Floating Tunnel) is an innovative solution for crossing large water areas with significant depths. The structure has a number of advantages compared to traditional solutions, such as cable-stayed and suspension bridges, an underwater tunnel made of immersed tubes, as well as a traditional tunnel. The main advantages are the ability to cross water obstacles with depths significantly exceeding the record values for bridges (60 m), as well as compensation of loads from its own weight by Archimedean force to ensure positive buoyancy. At the moment, not a single project has been implemented due to serious scientific problems, but the concept is attracting the attention of researchers from different countries, since the need for such structures will increase due to the need to reduce the time of transportation of bulk cargo on transcontinental routes. During operation, SFT structures are subject to various types of influences, including the effect of currents on the tunnel stiffening girder. Thus, the SFT contour shape has a key effect on the nature of the tunnel interaction with the current and determines the external forces that arise (drag force FD and ascending forces FL). The optimal SFT contour shape from the view point of interaction with the current allows one to predetermine the favorable operation of the structure under given conditions. In this article, the current impact on the SFT stiffening girder was assessed using a software package and the girder shape was optimized using gradient optimization capabilities. The article is part of the author’s dissertation research.
{"title":"Contour shape optimization of the submerged intercrossing water obstacles","authors":"V. Poliakov, Igor Khorev","doi":"10.15862/10sats223","DOIUrl":"https://doi.org/10.15862/10sats223","url":null,"abstract":"The submerged floating tunnel (also SFT from the English Submerged Floating Tunnel) is an innovative solution for crossing large water areas with significant depths. The structure has a number of advantages compared to traditional solutions, such as cable-stayed and suspension bridges, an underwater tunnel made of immersed tubes, as well as a traditional tunnel. The main advantages are the ability to cross water obstacles with depths significantly exceeding the record values for bridges (60 m), as well as compensation of loads from its own weight by Archimedean force to ensure positive buoyancy. At the moment, not a single project has been implemented due to serious scientific problems, but the concept is attracting the attention of researchers from different countries, since the need for such structures will increase due to the need to reduce the time of transportation of bulk cargo on transcontinental routes. During operation, SFT structures are subject to various types of influences, including the effect of currents on the tunnel stiffening girder. Thus, the SFT contour shape has a key effect on the nature of the tunnel interaction with the current and determines the external forces that arise (drag force FD and ascending forces FL). The optimal SFT contour shape from the view point of interaction with the current allows one to predetermine the favorable operation of the structure under given conditions. In this article, the current impact on the SFT stiffening girder was assessed using a software package and the girder shape was optimized using gradient optimization capabilities. The article is part of the author’s dissertation research.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction: Providing the span structure durability under dynamic influences is one of the main tasks in their design and construction. This task is accomplished mainly by studying the dynamic behavior of railway bridges when a train is moving. The paper considers the study of building a span structure finite element model under dynamic influences caused by a moving load on the main beam of railway bridge crossings. Methods: Construction members are designed by the finite element method in the Midas civil software package using rod finite elements. The dynamical analysis is carried out by the direct dynamic method in a linear setting. Fixed loads on the structure are transferred to the mass to meet the requirements of dynamic analysis. The rail is designed as a linear elastic Bernoulli-Euler beam of finite length, and the bridge is designed as a series of multi-span continuous Bernoulli-Euler beams. The interaction of the system (train — track — bridge) is designed by elastic elements. Results: An algorithm for calculating span structures under dynamic influences was created and a dynamic response of the structure was built. As a result of all the above, the dependences of the greatest vertical dynamic displacement and dynamic acceleration on time for different speeds were obtained. Discussion: This work made it possible to understand the principle of creating a linear mathematical model of the dynamic interaction of the system (bridge — train — railway) by the finite element method and presented an algorithm for calculating span structures under dynamic influences. The article showed the influence of train speed on the dynamic behavior of span structures, so it is necessary to take into account this influence on the parameters of the stress-strain state (vertical displacements).
{"title":"Finite element analysis of the span structures dynamics under a moving load influence","authors":"A. Barakat","doi":"10.15862/07sats223","DOIUrl":"https://doi.org/10.15862/07sats223","url":null,"abstract":"Introduction: Providing the span structure durability under dynamic influences is one of the main tasks in their design and construction. This task is accomplished mainly by studying the dynamic behavior of railway bridges when a train is moving. The paper considers the study of building a span structure finite element model under dynamic influences caused by a moving load on the main beam of railway bridge crossings. Methods: Construction members are designed by the finite element method in the Midas civil software package using rod finite elements. The dynamical analysis is carried out by the direct dynamic method in a linear setting. Fixed loads on the structure are transferred to the mass to meet the requirements of dynamic analysis. The rail is designed as a linear elastic Bernoulli-Euler beam of finite length, and the bridge is designed as a series of multi-span continuous Bernoulli-Euler beams. The interaction of the system (train — track — bridge) is designed by elastic elements. Results: An algorithm for calculating span structures under dynamic influences was created and a dynamic response of the structure was built. As a result of all the above, the dependences of the greatest vertical dynamic displacement and dynamic acceleration on time for different speeds were obtained. Discussion: This work made it possible to understand the principle of creating a linear mathematical model of the dynamic interaction of the system (bridge — train — railway) by the finite element method and presented an algorithm for calculating span structures under dynamic influences. The article showed the influence of train speed on the dynamic behavior of span structures, so it is necessary to take into account this influence on the parameters of the stress-strain state (vertical displacements).","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prefabricated circular tunnel linings are used in the construction of tunnels using the shield method, which significantly increases the speed and reduces the cost of building highways. Many methods have been developed for designing seismic resistant tunnel linings. Due to simplicity, analytical methods are usually used for preliminary design. In this case, the presence of joints between the blocks of the ring and between the rings is not taken into account. Compared to analytical methods, numerical methods, especially three-dimensional (3D), allow the most explicit consideration of the problem being solved. However, due to their complexity and time-consuming nature, 3D numerical models are only rarely used. In most reinforced concrete prefabricated linings, the deformation at the joints has a significant effect on the deformation of the rings. Thus, the magnitude and distribution of internal forces largely depend on the distribution and characteristics of the joints. Therefore, one of the most important factors in the design of a circular tunnel lining is the effect of segment connections on its overall behavior. This paper compares the internal forces that occur in the tunnel lining, determined using analytical analysis and numerical simulation in a three-dimensional formulation. When using numerical analysis methods, seismic loads are considered as quasi-static. However, almost all quasi-static analyzes presented in the literature include the same assumptions as closed form solutions and therefore have the same limited applicability. The main disadvantage of quasi-static models is that they do not take into account changes in the behavior of the structure over time.
{"title":"Numerical study of seismic resistance of prefabricated circular tunnel linings","authors":"Ilya Guskov, E. Pestryakova","doi":"10.15862/02sats223","DOIUrl":"https://doi.org/10.15862/02sats223","url":null,"abstract":"Prefabricated circular tunnel linings are used in the construction of tunnels using the shield method, which significantly increases the speed and reduces the cost of building highways. Many methods have been developed for designing seismic resistant tunnel linings. Due to simplicity, analytical methods are usually used for preliminary design. In this case, the presence of joints between the blocks of the ring and between the rings is not taken into account. Compared to analytical methods, numerical methods, especially three-dimensional (3D), allow the most explicit consideration of the problem being solved. However, due to their complexity and time-consuming nature, 3D numerical models are only rarely used. In most reinforced concrete prefabricated linings, the deformation at the joints has a significant effect on the deformation of the rings. Thus, the magnitude and distribution of internal forces largely depend on the distribution and characteristics of the joints. Therefore, one of the most important factors in the design of a circular tunnel lining is the effect of segment connections on its overall behavior. This paper compares the internal forces that occur in the tunnel lining, determined using analytical analysis and numerical simulation in a three-dimensional formulation. When using numerical analysis methods, seismic loads are considered as quasi-static. However, almost all quasi-static analyzes presented in the literature include the same assumptions as closed form solutions and therefore have the same limited applicability. The main disadvantage of quasi-static models is that they do not take into account changes in the behavior of the structure over time.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139372048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article investigates the issues related to the spray-on polymer waterproofing finishing structure of bridge structures at low temperatures, with a focus on thermophysical modeling and macroroughness normalization. Through patent research and a comparative analysis of polymeric materials for waterproofing bridge structures, the chosen object of study is the domestically manufactured polymeric material (three-layer structure) called «Hydroflex-1», along with its close analogues that exhibit adhesion to concrete and metal, homogeneous strength properties, suitable operating temperature range, fewer structural layers, and the longest proven service life. The author presents the process and results of computational modeling regarding the thermophysical interaction between the distribution of a flat flame of the waterproofing hot mixture and a treated surface. The results of mathematical thermophysical modeling are validated through the visualization of the temperature field of the sprayed hot waterproofing layer using a thermal imager. The calculation error deviates by no more than 5°C from the results of full-scale measurements. The formation of point caving occurs on the slopes of areas with maximum irregularities, which is influenced by the temperature and flow rate of the sprayed mixture, cooling time, as well as the angle and height of the macroroughness ledge. The technology for the spray-on structure of a three-layer polymeric waterproofing finishing for steel-reinforced concrete and metal orthotropic slabs of bridge structures during repair at low temperatures below 10°C has been improved. This improvement aims to extend the construction season by considering thermophysical modeling and normalizing geometric and statistical parameters of macroroughness. Additionally, the results of ranking the dominant factors influencing the thermophysical interaction are taken into account.
{"title":"Spray-on polymer waterproofing finishing structure for bridge structures, taking into account thermophysical modeling","authors":"Alexander Kamenskikh","doi":"10.15862/01sats223","DOIUrl":"https://doi.org/10.15862/01sats223","url":null,"abstract":"This article investigates the issues related to the spray-on polymer waterproofing finishing structure of bridge structures at low temperatures, with a focus on thermophysical modeling and macroroughness normalization. Through patent research and a comparative analysis of polymeric materials for waterproofing bridge structures, the chosen object of study is the domestically manufactured polymeric material (three-layer structure) called «Hydroflex-1», along with its close analogues that exhibit adhesion to concrete and metal, homogeneous strength properties, suitable operating temperature range, fewer structural layers, and the longest proven service life. The author presents the process and results of computational modeling regarding the thermophysical interaction between the distribution of a flat flame of the waterproofing hot mixture and a treated surface. The results of mathematical thermophysical modeling are validated through the visualization of the temperature field of the sprayed hot waterproofing layer using a thermal imager. The calculation error deviates by no more than 5°C from the results of full-scale measurements. The formation of point caving occurs on the slopes of areas with maximum irregularities, which is influenced by the temperature and flow rate of the sprayed mixture, cooling time, as well as the angle and height of the macroroughness ledge. The technology for the spray-on structure of a three-layer polymeric waterproofing finishing for steel-reinforced concrete and metal orthotropic slabs of bridge structures during repair at low temperatures below 10°C has been improved. This improvement aims to extend the construction season by considering thermophysical modeling and normalizing geometric and statistical parameters of macroroughness. Additionally, the results of ranking the dominant factors influencing the thermophysical interaction are taken into account.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139372003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Examination of the reinforced concrete structures state under the influence of organic corrosion environments showed a direct dependence of the nature of the platelet structure of concrete on the polyhydric alcohols adsorption activity of low concentrations. The author has proved the connection between the concrete organic corrosion and its destruction by organic substances, including polyhydric alcohols, aggressive towards cement stone and concrete, especially under the combined action of climatic factors — moistening and drying, freezing and thawing; in these cases, there is an accumulation of internal defects in the concrete in the form of microcracks, which lead to a decrease in its operational properties and further destruction of structures. Field studies conducted by the author included the study of the nature, causes and sources of aggressive secretions, which were monitored, the intensity of the secretions, the limits of distribution and the places of their accumulation were determined. Samples from the damaged areas were taken to clarify the damage nature and degree in the laboratory using physical, mechanical and chemical research methods. According to the inspections results, intensive destruction of the foundation sections under the tanks of finished products, elevated road’s reinforced concrete columns under the alcohol supply pipelines, and floors on acid-resistant tiles were detected. The reasons for the penetration of aggressive solutions through leaks and broken coatings of structures are shown. The inspection also made it possible to identify the causes of aggressive emissions: leakage, insufficient sealing of containers, spills during equipment operation, and others. The author has shown the negative impact of the simultaneous exposure to corrosion environment and low temperatures, and also found that with an increase in the content of mineral additives in the binder, the adsorption of polyhydric alcohols on the cement stone decreases. The high degree of the concrete pore space filling with solutions of polyhydric alcohols is also the main reason for their rapid destruction during frost exposure. Recommendations are given to improve the durability of structures by introducing hydraulic additives into the composition of the binder.
{"title":"Results analysis of building structure inspection operated in corrosion environment","authors":"V. Bratoshevskaya","doi":"10.15862/09sats223","DOIUrl":"https://doi.org/10.15862/09sats223","url":null,"abstract":"Examination of the reinforced concrete structures state under the influence of organic corrosion environments showed a direct dependence of the nature of the platelet structure of concrete on the polyhydric alcohols adsorption activity of low concentrations. The author has proved the connection between the concrete organic corrosion and its destruction by organic substances, including polyhydric alcohols, aggressive towards cement stone and concrete, especially under the combined action of climatic factors — moistening and drying, freezing and thawing; in these cases, there is an accumulation of internal defects in the concrete in the form of microcracks, which lead to a decrease in its operational properties and further destruction of structures. Field studies conducted by the author included the study of the nature, causes and sources of aggressive secretions, which were monitored, the intensity of the secretions, the limits of distribution and the places of their accumulation were determined. Samples from the damaged areas were taken to clarify the damage nature and degree in the laboratory using physical, mechanical and chemical research methods. According to the inspections results, intensive destruction of the foundation sections under the tanks of finished products, elevated road’s reinforced concrete columns under the alcohol supply pipelines, and floors on acid-resistant tiles were detected. The reasons for the penetration of aggressive solutions through leaks and broken coatings of structures are shown. The inspection also made it possible to identify the causes of aggressive emissions: leakage, insufficient sealing of containers, spills during equipment operation, and others. The author has shown the negative impact of the simultaneous exposure to corrosion environment and low temperatures, and also found that with an increase in the content of mineral additives in the binder, the adsorption of polyhydric alcohols on the cement stone decreases. The high degree of the concrete pore space filling with solutions of polyhydric alcohols is also the main reason for their rapid destruction during frost exposure. Recommendations are given to improve the durability of structures by introducing hydraulic additives into the composition of the binder.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article presents the abstract theorem and practical options for monitoring the technological process of a railway track object construction using expert technologies. Railway construction as a complex dynamic system requires certain resources for its maintenance. Under these conditions, effective control over the work execution technology performed during the construction of railway track facilities is of decisive importance. This can be achieved by improving the existing engineering and technical support system for railway construction through the introduction of a subsystem for engineering and technological processes intellectual support for the railway facilities construction. One of the subsystem tasks is the effective use of automation tools with elements of artificial intelligence. The appearance of deviations from the planned requirements during the construction work execution, due to the stochastic nature of railway construction, leads to technology violations, a decrease in productivity, an increase in labor costs, prime cost, an increase in duration and, as a result, a deterioration in the railway track object operational characteristics. In order to avoid such a development of events, periodic monitoring of the technological solutions implementation is necessary. To this end, as part of the methodology formation for engineering and intellectual support of railway construction technological processes, a system for monitoring the technological processes implementation for the railway facilities construction has been developed. Monitoring includes three stages: parameters registration, assessment and forecast of the technological process implementation. Taking into account the formalization peculiarities of a number of tasks to be solved, a method for registering the indicators of the technological process implementation on a time interval was developed and described. The results obtained at the assessment stage made it possible to determine the possibilities of using an expert system built on a probabilistic inference model for processing the results of monitoring the work progress during the railway facility construction. The logical inference mechanism is organized on a system of feedback and inference based on probabilistic Bayesian logic. The forecast of the technological process implementation is based on general methodological issues of the Markov random processes application. The predictive model and the method for obtaining quantitative characteristics of the forecast are based on the interpretation of the simplest flow properties in order to analyze the dynamics of changes in its states. Based on the results of a theoretical study, the article presents the practical aspects of monitoring the work execution processes in railway construction using expert technologies on the example of the construction of a flooded railway subgrade roadbed. The results presented in the article were obtained in the course of a dissertation r
{"title":"Monitoring of work execution processes in railway construction using expert technologies","authors":"A. Polyanskiy","doi":"10.15862/06sats123","DOIUrl":"https://doi.org/10.15862/06sats123","url":null,"abstract":"The article presents the abstract theorem and practical options for monitoring the technological process of a railway track object construction using expert technologies. Railway construction as a complex dynamic system requires certain resources for its maintenance. Under these conditions, effective control over the work execution technology performed during the construction of railway track facilities is of decisive importance. This can be achieved by improving the existing engineering and technical support system for railway construction through the introduction of a subsystem for engineering and technological processes intellectual support for the railway facilities construction. One of the subsystem tasks is the effective use of automation tools with elements of artificial intelligence.\u0000\u0000The appearance of deviations from the planned requirements during the construction work execution, due to the stochastic nature of railway construction, leads to technology violations, a decrease in productivity, an increase in labor costs, prime cost, an increase in duration and, as a result, a deterioration in the railway track object operational characteristics. In order to avoid such a development of events, periodic monitoring of the technological solutions implementation is necessary. To this end, as part of the methodology formation for engineering and intellectual support of railway construction technological processes, a system for monitoring the technological processes implementation for the railway facilities construction has been developed.\u0000\u0000Monitoring includes three stages: parameters registration, assessment and forecast of the technological process implementation. Taking into account the formalization peculiarities of a number of tasks to be solved, a method for registering the indicators of the technological process implementation on a time interval was developed and described. The results obtained at the assessment stage made it possible to determine the possibilities of using an expert system built on a probabilistic inference model for processing the results of monitoring the work progress during the railway facility construction. The logical inference mechanism is organized on a system of feedback and inference based on probabilistic Bayesian logic. The forecast of the technological process implementation is based on general methodological issues of the Markov random processes application. The predictive model and the method for obtaining quantitative characteristics of the forecast are based on the interpretation of the simplest flow properties in order to analyze the dynamics of changes in its states.\u0000\u0000Based on the results of a theoretical study, the article presents the practical aspects of monitoring the work execution processes in railway construction using expert technologies on the example of the construction of a flooded railway subgrade roadbed.\u0000\u0000The results presented in the article were obtained in the course of a dissertation r","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127154138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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