The advancing requirements for strength, relaxation, thermophysical, electrical, and other structural elements characteristics actualizes the polymer composite material use for the soft part and node point manufacture, which improves performance index. This paper reported the need to take into account relaxation phenomena in predicting the body’s thermal field development that is made of polymeric materials, and the thermal relaxation time and the thermal damping time proportional to the duration of transient thermal process certain periods. In this article three-period thermal process in a cylindrical body mathematical model is presented. cylindrical body made of a low-heat-conducting material by using a heat conduction hyperbolic equation that is reflecting the heat flow relaxation and thermal damping phenomenon. A numerical solution to the problem of unsteady heat conduction in a circular disk for a two-phase delay equation is presented, which is based on the grid method implementation by using a three-layer implicit difference scheme and the finite difference method use. Calculation formulas for the run-through coefficients as well as the temperature values at the outer boundaries are concluded using the boundary conditions approximation for the intermediate and upper time layers, taking into account the multi-period of the process. The implementation of the modified run-through method when solving the non-stationary heat conduction problem in a cylindrical body, taking into account the finite heat propagation speed and thermal damping is described. The calculation results for the cylindrical body temperature field are obtained by using the polymethyl methacrylate example upon sudden heating based on a model with a two-phase delay. The results presented in this paper aid in an increase in predicting temperature field accuracy in polymer composite materials in the transient thermal processes study.
{"title":"Cylindrical body temperature field simulation which made in the transitional thermal process conditions out of polymer material","authors":"L. Petrova, T. Gavrilova","doi":"10.15862/05sats320","DOIUrl":"https://doi.org/10.15862/05sats320","url":null,"abstract":"The advancing requirements for strength, relaxation, thermophysical, electrical, and other structural elements characteristics actualizes the polymer composite material use for the soft part and node point manufacture, which improves performance index. This paper reported the need to take into account relaxation phenomena in predicting the body’s thermal field development that is made of polymeric materials, and the thermal relaxation time and the thermal damping time proportional to the duration of transient thermal process certain periods.\u0000In this article three-period thermal process in a cylindrical body mathematical model is presented. cylindrical body made of a low-heat-conducting material by using a heat conduction hyperbolic equation that is reflecting the heat flow relaxation and thermal damping phenomenon.\u0000A numerical solution to the problem of unsteady heat conduction in a circular disk for a two-phase delay equation is presented, which is based on the grid method implementation by using a three-layer implicit difference scheme and the finite difference method use. Calculation formulas for the run-through coefficients as well as the temperature values at the outer boundaries are concluded using the boundary conditions approximation for the intermediate and upper time layers, taking into account the multi-period of the process. The implementation of the modified run-through method when solving the non-stationary heat conduction problem in a cylindrical body, taking into account the finite heat propagation speed and thermal damping is described.\u0000The calculation results for the cylindrical body temperature field are obtained by using the polymethyl methacrylate example upon sudden heating based on a model with a two-phase delay. The results presented in this paper aid in an increase in predicting temperature field accuracy in polymer composite materials in the transient thermal processes study.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114154920","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}
Permafrost soils are common for extensive areas of our country and when building engineering structures in such conditions, it is necessary to take into account the factor supporting subbase on the permafrost soil, which may initially have high stress-related characteristics. But the permafrost degradation phenomenon with frost retreat no less common. It can be happening both for natural reasons due to global warming, and for man-made reasons, when interference during construction and further the structure itself initiates subsoil frost retreat. For the most part, permafrost soils lose their strength and elastic properties during the frost retreat, turning into an almost liquid consistency, which entails the failure of the supports in the bearing capability and position stability. With the road network development and the bridge’s construction in the northern regions at the end of the 60s — early 70s of the XX century, the first principle of the design was widely applied. It was for use and maintenance of the subsoil in a frozen state, which means not require a deep foundation required. However, after 20 — 30 years of operation, cases of unexpected and significant bridge piers sagging began to be noted, as it turned out, was the result of permafrost soils frost retreat to the entire depth of the foundation. It was also noted that in some cases the bridge piers sagging is preceded by its frost boil phenomena, which appear shortly before piers sinking and almost complete failure. In this article case of an unexpected bridge piers failure examined on a specific bridge. After 30 years of proper functioning, pierces received such significant sagging, so in just three years that got to the point when it’s not only traffic safety but the cohesiveness of the entire structure. And before that, a frost boil was noted at some of the bridge pierce. The purpose of this study is to analyze the frost boil mechanism and sagging of the bridge pierce’ foundations due to the progressive permafrost degradation and to suggest restoring and maintaining ways for pierces’ operation capacity. Overall, the reasons and principles of permafrost subbase degradation were analyzed in this paper. through calculations using a specific example, significant sagging and bridge pierce bearing capability loss observations were justified and substantiated the effectiveness of the proposed in this article structural reinforcement measures.
{"title":"The bridge piers sagging problem under permafrost subbase degradation conditions and the possible solution","authors":"S. Tomilov, A. Sim, P. Grinev","doi":"10.15862/02sats320","DOIUrl":"https://doi.org/10.15862/02sats320","url":null,"abstract":"Permafrost soils are common for extensive areas of our country and when building engineering structures in such conditions, it is necessary to take into account the factor supporting subbase on the permafrost soil, which may initially have high stress-related characteristics. But the permafrost degradation phenomenon with frost retreat no less common. It can be happening both for natural reasons due to global warming, and for man-made reasons, when interference during construction and further the structure itself initiates subsoil frost retreat. For the most part, permafrost soils lose their strength and elastic properties during the frost retreat, turning into an almost liquid consistency, which entails the failure of the supports in the bearing capability and position stability.\u0000With the road network development and the bridge’s construction in the northern regions at the end of the 60s — early 70s of the XX century, the first principle of the design was widely applied. It was for use and maintenance of the subsoil in a frozen state, which means not require a deep foundation required. However, after 20 — 30 years of operation, cases of unexpected and significant bridge piers sagging began to be noted, as it turned out, was the result of permafrost soils frost retreat to the entire depth of the foundation. It was also noted that in some cases the bridge piers sagging is preceded by its frost boil phenomena, which appear shortly before piers sinking and almost complete failure.\u0000In this article case of an unexpected bridge piers failure examined on a specific bridge. After 30 years of proper functioning, pierces received such significant sagging, so in just three years that got to the point when it’s not only traffic safety but the cohesiveness of the entire structure. And before that, a frost boil was noted at some of the bridge pierce.\u0000The purpose of this study is to analyze the frost boil mechanism and sagging of the bridge pierce’ foundations due to the progressive permafrost degradation and to suggest restoring and maintaining ways for pierces’ operation capacity.\u0000Overall, the reasons and principles of permafrost subbase degradation were analyzed in this paper. through calculations using a specific example, significant sagging and bridge pierce bearing capability loss observations were justified and substantiated the effectiveness of the proposed in this article structural reinforcement measures.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128926511","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 paper studies the matters of multilayer asphalt-concrete systems cracking resistance, specifically we investigated the occurrence and development causes and peculiarities of the reflected cracks. In this study was examined the highways’ state of repair and the prerequisites for the defects formation on the pavement were determined, as well as the regional road structure operation aspect. The authors studied from every angle the causes of internal and external asphalt concrete pavements defects and deformations. The most popular filling of cracks technologies and restoring the pavement are were discussed in this paper, also the experience of roads repairing in the western part of Russia, Europe, and the USA was investigated. The determination results of the formation and develop-ment defects rate on the surface of the operated roads are presented in this article. Cracks in double-layer samples of finegrained asphalt concrete were simulated in laboratory conditions. A prototype model of 10 cm height and diameter were made by molding and densifying in layers, and a crack was laid in the lower layer of the prototype. Af-ter densifying samples were tested for compression. The physical modeling results analysis allows us to assume the dependence between the presence (or ab-sence) of pavement internal defects and the structural solidity. Mathematical modeling of the operation of a double-layer system was performed in the GenIDE32 software package to confirm the hypothesis. Evaluation of the stress-strain state by the finite element method showed the presence of system weakening characteristics zones around the defect area. There is increasing inter-nal stresses and deformations around the crack in a double-layer system, as well as a decrease in the overall system strength (stability). In the end, conclusions about the influence of asphalt-concrete pavement internal defects on the reflected cracks formation pro-cess were drawn.
{"title":"Reflected cracks buildups surveying and process simulation in double-layer asphalt-concrete systems","authors":"A. Kamenchukov, I. Ukrainskiy","doi":"10.15862/07SATS320","DOIUrl":"https://doi.org/10.15862/07SATS320","url":null,"abstract":"The paper studies the matters of multilayer asphalt-concrete systems cracking resistance, specifically we investigated the occurrence and development causes and peculiarities of the reflected cracks. In this study was examined the highways’ state of repair and the prerequisites for the defects formation on the pavement were determined, as well as the regional road structure operation aspect. The authors studied from every angle the causes of internal and external asphalt concrete pavements defects and deformations. The most popular filling of cracks technologies and restoring the pavement are were discussed in this paper, also the experience of roads repairing in the western part of Russia, Europe, and the USA was investigated. The determination results of the formation and develop-ment defects rate on the surface of the operated roads are presented in this article.\u0000Cracks in double-layer samples of finegrained asphalt concrete were simulated in laboratory conditions. A prototype model of 10 cm height and diameter were made by molding and densifying in layers, and a crack was laid in the lower layer of the prototype. Af-ter densifying samples were tested for compression. The physical modeling results analysis allows us to assume the dependence between the presence (or ab-sence) of pavement internal defects and the structural solidity.\u0000Mathematical modeling of the operation of a double-layer system was performed in the GenIDE32 software package to confirm the hypothesis. Evaluation of the stress-strain state by the finite element method showed the presence of system weakening characteristics zones around the defect area. There is increasing inter-nal stresses and deformations around the crack in a double-layer system, as well as a decrease in the overall system strength (stability). In the end, conclusions about the influence of asphalt-concrete pavement internal defects on the reflected cracks formation pro-cess were drawn.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124708153","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}
In this article, we present the abstract theorem and the feasibility for the implementation of the technological justification of the structural concept for track railway line objects using the expert system. Railway construction as a complex dynamic system requires certain resources for maintaining it. At the same time, it is characterized by the use of new, more advanced design solutions, materials, and technologies, the performers’ specialization development, and the attendant large number of participants in the technological process. Key role in these conditions gets effective standard operating procedures control, procedures that performed during the railway facilities construction. This can be achieved by improving the existing engineering and technical support system for railway construction by introducing an engineering and intellectual support subsystem for the technological processes of railway facilities construction. One of the tasks of technological processes engineering and intellectual support is the effective use of automated systems with artificial intelligence elements. Creation and implementation of automated systems with artificial intelligence elements are focused on achieving a single final result: a finished railway track facility of the corresponding functional purpose within the established deadlines planned prime cost and labor contribution and also up to date safety requirements throughout the entire operation period. Within the scope of the methodology formation for engineering and intellectual support of railway construction technological processes, the stages of constructive solutions technological substantiation for railway objects were considered, and the railway construction technological features were determined. The procedure for the railway track object decomposition into structural elements is described here. The results obtained at the decomposition stage made it possible to determine the possibilities of using expert systems to develop a technological process for the railway track object construction. With account taken of special factors relating to formalization series of tasks at hand. By the aid of the expert system, which was built based on the knowledge representation production model, was developed and described methodology for generating a construction works nomenclature. Based on theoretical research results, practical aspects of the technological substantiation implementation of design solutions using an expert system were presented here through the example of the railway roadbed flooded carn construction. During dissertation research done by the author, were obtained results that were presented in this article.
{"title":"Theory and practice of constructive solutions technological justification for railway objects via the use of an expert system","authors":"A. Polyanskiy","doi":"10.15862/01sats320","DOIUrl":"https://doi.org/10.15862/01sats320","url":null,"abstract":"In this article, we present the abstract theorem and the feasibility for the implementation of the technological justification of the structural concept for track railway line objects using the expert system. Railway construction as a complex dynamic system requires certain resources for maintaining it. At the same time, it is characterized by the use of new, more advanced design solutions, materials, and technologies, the performers’ specialization development, and the attendant large number of participants in the technological process. Key role in these conditions gets effective standard operating procedures control, procedures that performed during the railway facilities construction. This can be achieved by improving the existing engineering and technical support system for railway construction by introducing an engineering and intellectual support subsystem for the technological processes of railway facilities construction. One of the tasks of technological processes engineering and intellectual support is the effective use of automated systems with artificial intelligence elements. Creation and implementation of automated systems with artificial intelligence elements are focused on achieving a single final result: a finished railway track facility of the corresponding functional purpose within the established deadlines planned prime cost and labor contribution and also up to date safety requirements throughout the entire operation period.\u0000Within the scope of the methodology formation for engineering and intellectual support of railway construction technological processes, the stages of constructive solutions technological substantiation for railway objects were considered, and the railway construction technological features were determined. The procedure for the railway track object decomposition into structural elements is described here. The results obtained at the decomposition stage made it possible to determine the possibilities of using expert systems to develop a technological process for the railway track object construction. With account taken of special factors relating to formalization series of tasks at hand. By the aid of the expert system, which was built based on the knowledge representation production model, was developed and described methodology for generating a construction works nomenclature. Based on theoretical research results, practical aspects of the technological substantiation implementation of design solutions using an expert system were presented here through the example of the railway roadbed flooded carn construction.\u0000During dissertation research done by the author, were obtained results that were presented in this article.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127213772","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}
Temporary bridges are necessary to ensure movement during the construction or repair (reconstruction) of capital bridge structures, operational communication of interrupted tracks in various emergency situations, for one-time or seasonal transport communications. For this purpose, reusable mobile prefabricated structures are advisable. Inventory sets of collapsible bridges were designed and manufactured primarily in the interests of the military department, but are currently widely in demand and are used in the civilian sector of bridge building because of their economy, mobility, and accessibility in transportation. Among others, including modern collapsible bridge designs, the middle automobile collapsible bridge (CAPM), developed in 1968 and modernized in 1982 for the needs of the USSR Ministry of Defense, occupies a special place. In the process of withdrawing the CAPM sets stored in storage to the civilian construction sector, a significant demand for these structures was found to be due to their following advantages: complete staffing with all elements of the bridge, including supports; the possibility of overlapping spans of 18.6, 25.6, 32.6 m with the dimensions of the driving bed 4.2 m for single-track and 7.2 m for double-track passage Passport carrying capacity is designated as 40 tons for single-track passage and 60 tons for double-track passage. Since, according to a number of geometric and technical parameters, CAPM designs do not fully comply with the requirements of modern standards for capital bridges, their application is mainly oriented as temporary. It should be noted that with minor refinement – the installation of modern fences and a double-track transverse arrangement of sections for single-lane traffic, it is possible to achieve compliance with the required geometric parameters of the driving bed and the total lifting capacity for bridges on public roads of IV and V of technical category. The article considers the design feature of the pin mounting joints of sections of a collapsible span as a factor determining the carrying capacity, the nature of general deformations and, as a result, affecting the transport and operational characteristics of the bridge structure. The purpose of this study is to analyze the operation of the pin mounting joints of the sections of the spans of the CAPM with the assessment of the stress state of the elements of the connection node. We consider the novelty in the consideration of the issue to be an assessment of the strength of the elements of the pin joints and its effect on the general deformations – the deflections of the main beams.
临时桥梁是必要的，以确保在建造或修理(重建)主要桥梁结构期间的交通，在各种紧急情况下中断轨道的业务通信，以及一次性或季节性运输通信。为此，建议使用可重复使用的移动预制结构。可折叠桥梁库存组的设计和制造主要是为了军事部门的利益，但由于其经济、机动性和运输可达性，目前广泛需求并用于民用桥梁建设领域。在其他设计中，包括现代可折叠桥设计，中间汽车可折叠桥(CAPM)，于1968年开发，并于1982年为苏联国防部的需要进行了现代化改造，占据了特殊的地位。在将储存在仓库中的CAPM装置撤回民用建筑部门的过程中，发现对这些结构的需求很大，因为它们具有以下优点:配备桥梁的所有部件，包括支架;单轨通道4.2 m，双轨通道7.2 m，驱动床跨度18.6 m, 25.6 m, 32.6 m重叠的可能性护照的承载能力为单轨通道40吨，双轨通道60吨。由于CAPM设计在许多几何参数和技术参数上并不完全符合现代首都桥梁标准的要求，因此其应用主要是临时性的。值得注意的是，只要稍加改进——安装现代围栏和单车道交通路段的双轨横向布置，就有可能达到驱动床的几何参数要求和公共道路上桥梁的总起重能力达到技术类别IV和V。本文认为折叠式桥梁截面销安装节点的设计特点是决定桥梁承载能力和一般变形性质的一个因素，从而影响桥梁结构的运输和使用特性。本研究的目的是分析CAPM跨段销安装节点的运行情况，并评估连接节点单元的应力状态。我们认为在考虑这个问题时的新颖性是对销钉节点元素强度的评估及其对一般变形的影响-主梁的挠度。
{"title":"Influence of mounting joints of sections of a collapsible bridge on his stress-strain state","authors":"S. Tomilov","doi":"10.15862/25sats220","DOIUrl":"https://doi.org/10.15862/25sats220","url":null,"abstract":"Temporary bridges are necessary to ensure movement during the construction or repair (reconstruction) of capital bridge structures, operational communication of interrupted tracks in various emergency situations, for one-time or seasonal transport communications. For this purpose, reusable mobile prefabricated structures are advisable. Inventory sets of collapsible bridges were designed and manufactured primarily in the interests of the military department, but are currently widely in demand and are used in the civilian sector of bridge building because of their economy, mobility, and accessibility in transportation.\u0000Among others, including modern collapsible bridge designs, the middle automobile collapsible bridge (CAPM), developed in 1968 and modernized in 1982 for the needs of the USSR Ministry of Defense, occupies a special place. In the process of withdrawing the CAPM sets stored in storage to the civilian construction sector, a significant demand for these structures was found to be due to their following advantages: complete staffing with all elements of the bridge, including supports; the possibility of overlapping spans of 18.6, 25.6, 32.6 m with the dimensions of the driving bed 4.2 m for single-track and 7.2 m for double-track passage Passport carrying capacity is designated as 40 tons for single-track passage and 60 tons for double-track passage.\u0000Since, according to a number of geometric and technical parameters, CAPM designs do not fully comply with the requirements of modern standards for capital bridges, their application is mainly oriented as temporary.\u0000It should be noted that with minor refinement – the installation of modern fences and a double-track transverse arrangement of sections for single-lane traffic, it is possible to achieve compliance with the required geometric parameters of the driving bed and the total lifting capacity for bridges on public roads of IV and V of technical category.\u0000The article considers the design feature of the pin mounting joints of sections of a collapsible span as a factor determining the carrying capacity, the nature of general deformations and, as a result, affecting the transport and operational characteristics of the bridge structure.\u0000The purpose of this study is to analyze the operation of the pin mounting joints of the sections of the spans of the CAPM with the assessment of the stress state of the elements of the connection node. We consider the novelty in the consideration of the issue to be an assessment of the strength of the elements of the pin joints and its effect on the general deformations – the deflections of the main beams.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125377955","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}
In the article, the authors describe the methodology for determining the length of piles according to ASTM D5882. The authors of the article describe the situation that arose at one of the sites in the city of Tyumen when, when digging a pit, a previously constructed pile field with a grillage was discovered. The authors examined the pile field in order to determine the length of the piles. The length of piles immersed in the ground was determined by the method of acoustic wave excited in a pile by impact in accordance with ASTM D5882 Standard Test Method for Low Strain Impact Integrity Testing of Deep Foundations. The measurement method is based on the property of an acoustic wave being reflected from the interfaces between media with different acoustic impedances. The article describes the methodology for determining the length of piles with further processing of the measurement results. The main conclusions are formulated based on the results of the work on measuring the length of piles by the method of an acoustic wave excited in a pile by impact.
{"title":"Determination of the length of piles immersed in the soil by the method of an acoustic wave excited in a pile by impact","authors":"Dmitriy Skvortsov, Erkn Zhaisambaev, Denis Derevnin, Olesya Parenkina","doi":"10.15862/13sats220","DOIUrl":"https://doi.org/10.15862/13sats220","url":null,"abstract":"In the article, the authors describe the methodology for determining the length of piles according to ASTM D5882. The authors of the article describe the situation that arose at one of the sites in the city of Tyumen when, when digging a pit, a previously constructed pile field with a grillage was discovered. The authors examined the pile field in order to determine the length of the piles. The length of piles immersed in the ground was determined by the method of acoustic wave excited in a pile by impact in accordance with ASTM D5882 Standard Test Method for Low Strain Impact Integrity Testing of Deep Foundations. The measurement method is based on the property of an acoustic wave being reflected from the interfaces between media with different acoustic impedances. The article describes the methodology for determining the length of piles with further processing of the measurement results. The main conclusions are formulated based on the results of the work on measuring the length of piles by the method of an acoustic wave excited in a pile by impact.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122462016","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 paper considers the problem of using modern types of concrete, in particular self-compacting concrete, fiber concrete and ultra-high-strength concrete. The issues of the importance of analyzing the possibility of using innovative types of concrete were raised in order to improve the quality of the resulting structures, increase their durability, reduce labor costs, reduce the time of work. The principle of operation of self-compacting concrete and concrete using various fibers instead of conventional reinforcement is described. Their strength characteristics are shown, the principle of operation, the features of its use, as well as manufacturing methods are described. The main types of fibers, both metallic and non-metallic, are distinguished, their main features are described. It also discusses the importance of adhering to the technology for laying concrete mixtures and how to care for them. Examples of their possible and actual use in transport construction and not only are given. The experience of using self-compacting concrete and fiber concrete in tunneling, bridge building. The issues of their development and features of their application are raised. The importance of their use from an environmental point of view (the use of recycled materials) is noted. A comparison of the main mechanical characteristics of several types of concrete (ultrahigh-strength concrete, high-strength concrete, ordinary concrete) is carried out. The principle of tensile operation of ultrahigh-strength concrete in comparison with other materials is considered. Using the authors’ works as an example, the work emphasizes the importance of further research of these materials, the development of regulatory documentation for further implementation in various areas of construction, the importance of developing new types of reinforced concrete structures with new section shapes, which is possible with the correct approach and use of modern materials, is emphasized.
{"title":"Features of application of modern types of concrete in transport construction","authors":"Maksim Varakin, I. Ovchinnikov","doi":"10.15862/22sats220","DOIUrl":"https://doi.org/10.15862/22sats220","url":null,"abstract":"The paper considers the problem of using modern types of concrete, in particular self-compacting concrete, fiber concrete and ultra-high-strength concrete.\u0000The issues of the importance of analyzing the possibility of using innovative types of concrete were raised in order to improve the quality of the resulting structures, increase their durability, reduce labor costs, reduce the time of work. The principle of operation of self-compacting concrete and concrete using various fibers instead of conventional reinforcement is described. Their strength characteristics are shown, the principle of operation, the features of its use, as well as manufacturing methods are described. The main types of fibers, both metallic and non-metallic, are distinguished, their main features are described. It also discusses the importance of adhering to the technology for laying concrete mixtures and how to care for them. Examples of their possible and actual use in transport construction and not only are given.\u0000The experience of using self-compacting concrete and fiber concrete in tunneling, bridge building. The issues of their development and features of their application are raised. The importance of their use from an environmental point of view (the use of recycled materials) is noted.\u0000A comparison of the main mechanical characteristics of several types of concrete (ultrahigh-strength concrete, high-strength concrete, ordinary concrete) is carried out. The principle of tensile operation of ultrahigh-strength concrete in comparison with other materials is considered.\u0000Using the authors’ works as an example, the work emphasizes the importance of further research of these materials, the development of regulatory documentation for further implementation in various areas of construction, the importance of developing new types of reinforced concrete structures with new section shapes, which is possible with the correct approach and use of modern materials, is emphasized.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128929461","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}
Due to the fact that modern bridge construction sets itself the task of building new bridge structures in seismically active areas where earthquakes or other external impacts are permanent, there is an urgent question of protecting the structure from these impacts. This article is devoted to the analysis of ways to protect the bridge structure from external influences. The author analyzes these methods on the basis of publicly available data from companies engaged in the production of structures that prevent external influences, as well as on the basis of modern regulatory documents. The article presents such methods of protection as: deformation seams, support parts, dampers of various modifications and vibration dampers of shrouds. To choose the optimal method, both from the economic side and from the technical side, it is necessary to make verification calculations for static, dynamic and seismic effects, study the geological characteristics of the construction site, conduct mandatory tests of the structures used, as well as use regulatory documents and guidelines for testing and using seismic isolation devices. Also, the author of the article emphasizes that it is important to study ways to protect bridge structures not only in domestic practice, but also in foreign practice.
{"title":"Comparative analysis of ways to protect bridge structures from external influences","authors":"Stanislav Berlov, I. Ovchinnikov","doi":"10.15862/20sats220","DOIUrl":"https://doi.org/10.15862/20sats220","url":null,"abstract":"Due to the fact that modern bridge construction sets itself the task of building new bridge structures in seismically active areas where earthquakes or other external impacts are permanent, there is an urgent question of protecting the structure from these impacts. This article is devoted to the analysis of ways to protect the bridge structure from external influences. The author analyzes these methods on the basis of publicly available data from companies engaged in the production of structures that prevent external influences, as well as on the basis of modern regulatory documents. The article presents such methods of protection as: deformation seams, support parts, dampers of various modifications and vibration dampers of shrouds. To choose the optimal method, both from the economic side and from the technical side, it is necessary to make verification calculations for static, dynamic and seismic effects, study the geological characteristics of the construction site, conduct mandatory tests of the structures used, as well as use regulatory documents and guidelines for testing and using seismic isolation devices. Also, the author of the article emphasizes that it is important to study ways to protect bridge structures not only in domestic practice, but also in foreign practice.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125992756","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}
Due to the increase in requirements for transport facilities, there is a need to strengthen them. The article is devoted to the analysis of reinforcement methods for load-bearing reinforced concrete structures of transport structures. The author notes in what period of the bridge’s life, it needs reinforcement, what difficulties are associated with reinforcing structures, and what are the main amplification methods that exist today. In order to select the optimal amplification method, it is necessary to carry out verification calculations, study the zone requiring amplification, take into account how many times the load-bearing capacity will increase and whether additional force effects will occur. This article describes the advantages and disadvantages of reinforcing by welding additional reinforcement and bonding composite material. The author calculated the amplification of the extended zone of the T-section reinforced concrete beam of the superstructure with additional reinforcement and composite materials. Based on the calculations made, recommendations have been put forward on the relevance of using one or another method of reinforcing the structure.
{"title":"Comparative analysis of reinforced concrete tee beams reinforcement methods","authors":"Danil Baldin, Andrey Kraev, Erkn Zhaisambaev","doi":"10.15862/05sats220","DOIUrl":"https://doi.org/10.15862/05sats220","url":null,"abstract":"Due to the increase in requirements for transport facilities, there is a need to strengthen them. The article is devoted to the analysis of reinforcement methods for load-bearing reinforced concrete structures of transport structures. The author notes in what period of the bridge’s life, it needs reinforcement, what difficulties are associated with reinforcing structures, and what are the main amplification methods that exist today. In order to select the optimal amplification method, it is necessary to carry out verification calculations, study the zone requiring amplification, take into account how many times the load-bearing capacity will increase and whether additional force effects will occur. This article describes the advantages and disadvantages of reinforcing by welding additional reinforcement and bonding composite material. The author calculated the amplification of the extended zone of the T-section reinforced concrete beam of the superstructure with additional reinforcement and composite materials. Based on the calculations made, recommendations have been put forward on the relevance of using one or another method of reinforcing the structure.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117214722","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}
In recent years, the approach to experimental and statistical research and optimization of complex multicomponent systems has changed radically. In various fields of scientific and technical research, methods of mathematical planning of experiments are successfully used. Their wide application significantly increases the effectiveness of research, as well as proves their universality and suitability in most studies of building materials. As a result, the authors present a method of mathematical planning of the experiment, which is used to optimize the composition and properties of modified mixtures for rough thin-layer coatings. This method allows a fairly complete and comprehensive assessment of the effect of components on the properties of modified mixtures and to obtain a mathematical model of the process in graphical form, as well as to obtain a theoretical model for evaluating and predicting the physical, mechanical and operational properties of the materials under study. In this article, the first stage of research was used to select the percentage of binder, hydrate lime and additives, and also studied the influence of the variation factor of these components on the physical and mechanical properties of the mixture. At the second stage, changes in response functions were investigated. The results of a complete three-factor experiment allowed us to establish rational ranges of values of the studied components in order to obtain mixtures for rough concolay coatings with optimal values of physical, mechanical and operational parameters.
{"title":"Modeling of compositions and predicting properties of modified mixtures for rough thin-layer coatings","authors":"D. Chernykh, Mihail Pakin","doi":"10.15862/16sats220","DOIUrl":"https://doi.org/10.15862/16sats220","url":null,"abstract":"In recent years, the approach to experimental and statistical research and optimization of complex multicomponent systems has changed radically. In various fields of scientific and technical research, methods of mathematical planning of experiments are successfully used. Their wide application significantly increases the effectiveness of research, as well as proves their universality and suitability in most studies of building materials.\u0000As a result, the authors present a method of mathematical planning of the experiment, which is used to optimize the composition and properties of modified mixtures for rough thin-layer coatings. This method allows a fairly complete and comprehensive assessment of the effect of components on the properties of modified mixtures and to obtain a mathematical model of the process in graphical form, as well as to obtain a theoretical model for evaluating and predicting the physical, mechanical and operational properties of the materials under study.\u0000In this article, the first stage of research was used to select the percentage of binder, hydrate lime and additives, and also studied the influence of the variation factor of these components on the physical and mechanical properties of the mixture. At the second stage, changes in response functions were investigated.\u0000The results of a complete three-factor experiment allowed us to establish rational ranges of values of the studied components in order to obtain mixtures for rough concolay coatings with optimal values of physical, mechanical and operational parameters.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128417065","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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