The pipeline construction in complex engineering-geological conditions requires a thorough initial data analysis, as well as complex slope modeling using modern software systems. The article discusses the features of the foundation construction for stand-alone supports for power lines and pipelines on landslide slopes composed of clay soils. Relevant Russian regulations documents administer above-ground pipelining, which significantly complicates the design process. However, above-ground pipelining allows monitoring the slope condition (formation road edge breakaway), foundations (deviation from the design location), as well as the pipeline (displacement of the route axis, the state of welds). Timely detected deviations allow avoiding an emergency situation. The author considers possible options for constructive solutions for support foundations, as well as protective structures exemplified by a real Krasnodar Krai object. The pipeline construction in active landslide displacements conditions, as well as the presence of seismic effects, requires not only ensuring the construction's economic feasibility, but also the work safety. In the developing process of optimal design solutions, slope computer modeling was executed both in two-dimensional and three-dimensional formulations based on the finite element method using the Plaxis 2D and Plaxis 3D programs. The considered design situations made it possible to take into account the worst load combinations possible during pipeline operation. According to the calculation results and a comprehensive engineering and geological conditions study at the site, as well as the construction organization peculiarities, a block diagram has been developed that makes it possible to determine the optimal design solutions for protective structures in relation to any landslide construction site.
{"title":"Design peculiarities of pipeline support on landslide slopes","authors":"D. Leyer, Dmitry Seryi, Nikolai Lubarsky","doi":"10.15862/02sats321","DOIUrl":"https://doi.org/10.15862/02sats321","url":null,"abstract":"The pipeline construction in complex engineering-geological conditions requires a thorough initial data analysis, as well as complex slope modeling using modern software systems. The article discusses the features of the foundation construction for stand-alone supports for power lines and pipelines on landslide slopes composed of clay soils. Relevant Russian regulations documents administer above-ground pipelining, which significantly complicates the design process. However,\u0000above-ground pipelining allows monitoring the slope condition (formation road edge breakaway), foundations (deviation from the design location), as well as the pipeline (displacement of the route axis, the state of welds). Timely detected deviations allow avoiding an emergency situation.\u0000The author considers possible options for constructive solutions for support foundations, as well as protective structures exemplified by a real Krasnodar Krai object. The pipeline construction in active landslide displacements conditions, as well as the presence of seismic effects, requires not only ensuring the construction's economic feasibility, but also the work safety. In the developing process of optimal design solutions, slope computer modeling was executed both in two-dimensional and three-dimensional formulations based on the finite element method using the Plaxis 2D and Plaxis 3D programs. The considered design situations made it possible to take into account the worst load combinations possible during pipeline operation. According to the calculation results and a comprehensive engineering and geological conditions study at the site, as well as the construction organization peculiarities, a block diagram has been developed that makes it possible to determine the optimal design solutions for protective structures in relation to any landslide construction site.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116220444","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 investigated the possibility of using the thermal control method for diagnosing fatigue cracks in the metal superstructure, determined the necessary parameters for that control method. The studies were conducted during cantilevered steel samples fatigue tests simulating the superstructure beam wall operation, reinforced with stiffening ribs. To carry out the experiments were developed a test setup and a loading procedure at the various intensity of exposure. An electric motor with eccentrics is used as a loading device. The sample surface heating was recorded by thermal imagers with 0.03 K and 0.05 K temperature sensitivities and 60 frames/s and 9 frames/s shooting speed, respectively. Was confirmed the possibility of determining crack presence before its emergence to the surface namely at the stage of its initiation, and also were determined the self-heating zone dimensions at the tip of a crack. The conducting a laboratory experiment technique on the dissipative processes study in the metal superstructure elements is described.
{"title":"Experimental studies of the energy dissipation processes at the tops of fatigue cracks in the elements of bridge structures","authors":"L. Solovyev, V. Fedorenko","doi":"10.15862/04sats321","DOIUrl":"https://doi.org/10.15862/04sats321","url":null,"abstract":"In the article, the authors investigated the possibility of using the thermal control method for diagnosing fatigue cracks in the metal superstructure, determined the necessary parameters for that control method. The studies were conducted during cantilevered steel samples fatigue tests simulating the superstructure beam wall operation, reinforced with stiffening ribs. To carry out the experiments were developed a test setup and a loading procedure at the various intensity of exposure. An electric motor with eccentrics is used as a loading device. The sample surface heating was recorded by thermal imagers with 0.03 K and 0.05 K temperature sensitivities and 60 frames/s and 9 frames/s shooting speed, respectively. Was confirmed the possibility of determining crack presence before its emergence to the surface namely at the stage of its initiation, and also were determined the self-heating zone dimensions at the tip of a crack. The conducting a laboratory experiment technique on the dissipative processes study in the metal superstructure elements is described.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127447551","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}
Pile-supported retaining structures are widely used to protect road sections from landslide processes. The article describes the design and calculation peculiarities of pile-supported retaining structures reinforced with a drill and inject anchors from tubular screw rods. The authors considered two options for this type of anchors setup: without free length and with a pre-set free length. In the software geotechnical complex Plaxis, on the finite element method basis, mathematical modeling and calculation of a pile-supported anchor retaining structure with different free anchors lengths from tubular screw rods for various soils types have been performed. Numerical relationships have been obtained between the anchors' free length and the resulting forces in the retaining structure. The performed calculations series of the test scheme showed that with an increase in the free anchors' length in the retaining structure, there is a decrease in the applied load in its load-bearing elements due to the horizontal displacements growth. The article presents the survey results of a real road section, on which a landslide displacement is being prepared, and considers a design solution for a pile-supported anchor retaining structure to ensure its safe operation. Performed a series of calculations for various landslide process development stages in this area showed that the effect of the anchors' free length also largely depends on the state of the adjacent soil mass. Obtained results clearly show that the design of a free length section for anchors made of tubular screw rods makes it possible to design more cost-effective pile-supported anchor holding structures without reducing their reliability.
{"title":"Effect of the anchors' free length that made of tubular screw rods on the forces distribution in pile-anchor retaining structures on highways","authors":"Nikolai Lubarsky, D. Leyer","doi":"10.15862/05SATS221","DOIUrl":"https://doi.org/10.15862/05SATS221","url":null,"abstract":"Pile-supported retaining structures are widely used to protect road sections from landslide processes. The article describes the design and calculation peculiarities of pile-supported retaining structures reinforced with a drill and inject anchors from tubular screw rods. The authors considered two options for this type of anchors setup: without free length and with a pre-set free length. In the software geotechnical complex Plaxis, on the finite element method basis, mathematical modeling and calculation of a pile-supported anchor retaining structure with different free anchors lengths from tubular screw rods for various soils types have been performed. Numerical relationships have been obtained between the anchors' free length and the resulting forces in the retaining structure. The performed calculations series of the test scheme showed that with an increase in the free anchors' length in the retaining structure, there is a decrease in the applied load in its load-bearing elements due to the horizontal displacements growth. The article presents the survey results of a real road section, on which a landslide displacement is being prepared, and considers a design solution for a pile-supported anchor retaining structure to ensure its safe operation. Performed a series of calculations for various landslide process development stages in this area showed that the effect of the anchors' free length also largely depends on the state of the adjacent soil mass. Obtained results clearly show that the design of a free length section for anchors made of tubular screw rods makes it possible to design more cost-effective pile-supported anchor holding structures without reducing their reliability.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115099326","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 structural concepts peculiarities of bridge structures for mountain conditions were analyzed. It is noted that the mountainous terrain is characterized not only by a complex broken rock but also by the course of earthquakes and their genetic varieties: landslides, avalanches, rockfalls, etc. It is also noted that the interaction of the plain bridge and the environment is one-sided, while mountainous bridges themselves are negatively influenced by the mountainous environment. The Republic of Dagestan territory is considered an example of mountainous terrain. The linking bridge structures problem to various mountainous terrain regions is investigated here. The peculiarity of the mountain rivers and bridge crossings interaction is noted in this paper, as well as the influence of rivers on the constructive justification of the mountain bridges solutions. The possibility of using cascade systems for regulating the mountain rivers water regime for the rational bridge crossings design with several holes is considered. Various options for the bridge crossings placement relative to mountain rivers are given as well as described their peculiarities. Current support parts and expansion joints are considered and analyzed from the mountain bridge use on structures suitability point of view. The necessity of using seismic-insulating expansion joints and their influence on the conditions of vehicles passing through the bridge structure during an earthquake is substantiated here. The problem of using road pavements on mountain bridge structures is noted, the most common road pavements designs are described and analyzed. The concepts of the «ideal» bridge and their applied significance in relation to mountainous terrain are presented. The constructive and technological solutions considered within the framework of this article will improve the bridge structure’s efficiency in mountainous conditions.
{"title":"Constructive and technological substantiation of constructive solutions for mountain bridge structures","authors":"M. Magomedov, I. Ovchinnikov","doi":"10.15862/12sats221","DOIUrl":"https://doi.org/10.15862/12sats221","url":null,"abstract":"In this article structural concepts peculiarities of bridge structures for mountain conditions were analyzed. It is noted that the mountainous terrain is characterized not only by a complex broken rock but also by the course of earthquakes and their genetic varieties: landslides, avalanches, rockfalls, etc. It is also noted that the interaction of the plain bridge and the environment is one-sided, while mountainous bridges themselves are negatively influenced by the mountainous environment. The Republic of Dagestan territory is considered an example of mountainous terrain. The linking bridge structures problem to various mountainous terrain regions is investigated here.\u0000The peculiarity of the mountain rivers and bridge crossings interaction is noted in this paper, as well as the influence of rivers on the constructive justification of the mountain bridges solutions. The possibility of using cascade systems for regulating the mountain rivers water regime for the rational bridge crossings design with several holes is considered. Various options for the bridge crossings placement relative to mountain rivers are given as well as described their peculiarities.\u0000Current support parts and expansion joints are considered and analyzed from the mountain bridge use on structures suitability point of view. The necessity of using seismic-insulating expansion joints and their influence on the conditions of vehicles passing through the bridge structure during an earthquake is substantiated here. The problem of using road pavements on mountain bridge structures is noted, the most common road pavements designs are described and analyzed. The concepts of the «ideal» bridge and their applied significance in relation to mountainous terrain are presented.\u0000The constructive and technological solutions considered within the framework of this article will improve the bridge structure’s efficiency in mountainous conditions.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115590931","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}
V. Erofeev, B. Bondarev, Valerij Kruglov, M. Gavrilov, A. Rodin, I. Erofeeva, A. Bondarev, A. Filatov, A. Martynov, Ilya Vostrikov
The article is dedicated to the construction mix technology development and the study intended for the bridgework damaged structures repair. It presents the results of a study of composites made on the concrete and polymer binders basis. It is shown that the main factors affecting the hydraulic structures' structural elements' durability are both dynamic and mobile loads from the effects of the vehicles, and chemical effects from impurities contained in the water passing through the structure as well as biological effects from bacteria and filamentous fungi. Previously in the article "Bridges maintainability evaluation peculiarities as part of hydraulic structures" were given hydraulic structures inspection results, found various defects and damages: cracks, chips, peeling, etc. In this article, to eliminate such defects were proposed the compositions of varnish-and-paint, mastic mixtures, and resin concrete. For the structure's repair with significant damage, were proposed powder-activated concrete use. In the experimental research process, the cement and polymer concrete compositions with improved strength and other properties recommended for use in power loads conditions, chemical and biological aggressive media, were established. Recommended for use as binders for biocidal cement. presented technological operations for repair work using cement and polymer mixtures. The developed composites' practical use is advisable, including in the structural defects elimination course in hydraulic structures located outdoors in zones with thermal and humidity cycling.
{"title":"Development and research of cement and polymer composites for bridge structure repair","authors":"V. Erofeev, B. Bondarev, Valerij Kruglov, M. Gavrilov, A. Rodin, I. Erofeeva, A. Bondarev, A. Filatov, A. Martynov, Ilya Vostrikov","doi":"10.15862/04sats221","DOIUrl":"https://doi.org/10.15862/04sats221","url":null,"abstract":"The article is dedicated to the construction mix technology development and the study intended for the bridgework damaged structures repair. It presents the results of a study of composites made on the concrete and polymer binders basis. It is shown that the main factors affecting the hydraulic structures' structural elements' durability are both dynamic and mobile loads from the effects of the vehicles, and chemical effects from impurities contained in the water passing through the structure as well as biological effects from bacteria and filamentous fungi. Previously in the article \"Bridges maintainability evaluation peculiarities as part of hydraulic structures\" were given hydraulic structures inspection results, found various defects and damages: cracks, chips, peeling, etc. In this article, to eliminate such defects were proposed the compositions of varnish-and-paint, mastic mixtures, and resin concrete. For the structure's repair with significant damage, were proposed powder-activated concrete use. In the experimental research process, the cement and polymer concrete compositions with improved strength and other properties recommended for use in power loads conditions, chemical and biological aggressive media, were established. Recommended for use as binders for biocidal cement. presented technological operations for repair work using cement and polymer mixtures. The developed composites' practical use is advisable, including in the structural defects elimination course in hydraulic structures located outdoors in zones with thermal and humidity cycling.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125741875","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 existing approaches for reducing the differential settlements of buildings and structures have their own advantages and disadvantages. Lowering of a building or part of it is one of the promising methods to reduce the differential settlements of shallow foundations resting upon weak silt-loam soils. The effect is achieved by drilling-out vertical boreholes in the immediate vicinity of the foundation from the minimal settlements. Method: Russian and foreign scientists have been involved in the development of calculation procedures for horizontal and inclined drilling-out of boreholes. It has been important to determine drilling parameters when using this technology and how soil characteristics and stress state of soils around the borehole influence the reduction of differential settlements. The paper discusses the influence of the strength characteristics of soils on the stress state of the soil massif around the borehole, as well as the influence of the borehole radius on the formed areas of limit state. The analytical solution is based on the well-known ratio used to determine the stress state around the borehole during pressure tests. Tangential and radial stresses are determined from this ratio; next, they are checked according to the condition of the strength law, and thus, the stress state around the borehole becomes evident. Result: The stress state of the soil around the boreholes has been calculated by the given method; it has made it possible to calculate the areas of soil destruction and determine the parameters of boreholes and their geometry depending on the purposes when regulating the settlements of slab foundations. It has been established that drilling behind the foundation contour in relation to drilling in the foundation contour makes it possible to increase the radius of the plastic deformation zone up to two times under the same soil conditions and well geometry.
{"title":"Stress-strain state of a borehole determined analytically using drilling-out as a technology of reducing differential settlement","authors":"Y. Pronozin, M. Kajgorodov, A. Gerber","doi":"10.15862/08sats221","DOIUrl":"https://doi.org/10.15862/08sats221","url":null,"abstract":"The existing approaches for reducing the differential settlements of buildings and structures have their own advantages and disadvantages. Lowering of a building or part of it is one of the promising methods to reduce the differential settlements of shallow foundations resting upon weak silt-loam soils. The effect is achieved by drilling-out vertical boreholes in the immediate vicinity of the foundation from the minimal settlements. Method: Russian and foreign scientists have been involved in the development of calculation procedures for horizontal and inclined drilling-out of boreholes. It has been important to determine drilling parameters when using this technology and how soil characteristics and stress state of soils around the borehole influence the reduction of differential settlements. The paper discusses the influence of the strength characteristics of soils on the stress state of the soil massif around the borehole, as well as the influence of the borehole radius on the formed areas of limit state. The analytical solution is based on the well-known ratio used to determine the stress state around the borehole during pressure tests. Tangential and radial stresses are determined from this ratio; next, they are checked according to the condition of the strength law, and thus, the stress state around the borehole becomes evident. Result: The stress state of the soil around the boreholes has been calculated by the given method; it has made it possible to calculate the areas of soil destruction and determine the parameters of boreholes and their geometry depending on the purposes when regulating the settlements of slab foundations. It has been established that drilling behind the foundation contour in relation to drilling in the foundation contour makes it possible to increase the radius of the plastic deformation zone up to two times under the same soil conditions and well geometry.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130182967","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 discusses the interaction issue between the track and the rolling stock to determine the forces working on the track during the passage of a rolling load, and their further distribution through the ballast bed. The study aims to determine the vertical pressure profile working on the orthotropic metal ballast bed slab of the railway superstructure. To determine the load share from the rolling stock transferred from the rails to the cross-sleepers, the rail is represented as a beam of infinite length with one or several concentrated forces. To determine the cross-sleeper stress-strain state, it is considered as a short beam on a cushion course. The article presents the substantiation of the flow mechanics formulas application possibility to the ballast bed. Based on the Boussinesq problem solution, calculation formulas are obtained for determining the pressure along with the ballast bed plate. The results obtained by the proposed method were compared with other authors’ experimental data and the finite element modeling results in the Midas FEA software package. The analysis took into account the design features of the ballast bed plates and the track superstructure on the existing superstructures. A theoretical study of the influence of the sheet of the covering bending stiffness on the pressure profile northing is carried out. The proposed method is applicable for various superstructure and the ballast bed slab, and also takes into account the uneven pressure distribution on the inner and outer rails from the trainload, changes in eccentricity along the length of the structure, different thickness of the ballast bed under the cross-sleepers ends, as well as the effect of centrifugal force.
{"title":"Pressure profile definition over the metal orthotropic deck surface of the decking superstructure ballast pocket from the local load action","authors":"I. Zasukhin","doi":"10.15862/09sats221","DOIUrl":"https://doi.org/10.15862/09sats221","url":null,"abstract":"The article discusses the interaction issue between the track and the rolling stock to determine the forces working on the track during the passage of a rolling load, and their further distribution through the ballast bed. The study aims to determine the vertical pressure profile working on the orthotropic metal ballast bed slab of the railway superstructure. To determine the load share from the rolling stock transferred from the rails to the cross-sleepers, the rail is represented as a beam of infinite length with one or several concentrated forces. To determine the cross-sleeper stress-strain state, it is considered as a short beam on a cushion course. The article presents the substantiation of the flow mechanics formulas application possibility to the ballast bed. Based on the Boussinesq problem solution, calculation formulas are obtained for determining the pressure along with the ballast bed plate. The results obtained by the proposed method were compared with other authors’ experimental data and the finite element modeling results in the Midas FEA software package. The analysis took into account the design features of the ballast bed plates and the track superstructure on the existing superstructures. A theoretical study of the influence of the sheet of the covering bending stiffness on the pressure profile northing is carried out. The proposed method is applicable for various superstructure and the ballast bed slab, and also takes into account the uneven pressure distribution on the inner and outer rails from the trainload, changes in eccentricity along the length of the structure, different thickness of the ballast bed under the cross-sleepers ends, as well as the effect of centrifugal force.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129686672","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 author considers the verification issue of the endurance of the venture elements of steel-reinforced concrete spans of bridges, in particular, flexible dowel crutches («Nelson’s anchors»). According to the existing domestic regulatory framework, the endurance test of the flexible dowel crutches for road bridges is not required; at the same time, the survey’s results of the operated superstructures indicate the presence of problems associated with the insufficient endurance of these elements. The article presents comprehensive (qualitative and quantitative) comparative analysis results of the world’s existing approaches to testing the endurance of the venture elements. At the stage of qualitative analysis, the author considered methods of checking the endurance of elements in general according to the norms of 8 countries and regions (Russia, the European Union, the USA, Ukraine, Australia, Canada, Japan, China) and highlighted a basic set of methods for checking the endurance of the venture elements (Russia, the European Union, USA, Ukraine). The models of the basic set were subjected to a detailed qualitative analysis according to the criteria of the models used and the parameters included in them. The quantitative analysis of the selected basic set techniques, carried out in relation to the existing bridge, included an analysis of the effects of moving loads on the venture elements, direct elements verification using the considered methods, as well as the design damage comparison of the elements obtained by the Palmgren-Miner linear summation hypothesis. Based on the obtained values of design damage, the values of the use of endurance reserves were determined and analyzed for each of the considered methods and the conditional load model. Based on the results of the qualitative and quantitative analysis, the author draws conclusions based on the comparison of various methods and highlights the rational directions for improving the existing domestic methodology.
{"title":"Comprehensive analysis of existing endurance testing methods of flexible dowel crutches of composite reinforced concrete road bridges according to the standards of a number of countries","authors":"Nikolai Kozak","doi":"10.15862/10sats221","DOIUrl":"https://doi.org/10.15862/10sats221","url":null,"abstract":"In the article, the author considers the verification issue of the endurance of the venture elements of steel-reinforced concrete spans of bridges, in particular, flexible dowel crutches («Nelson’s anchors»). According to the existing domestic regulatory framework, the endurance test of the flexible dowel crutches for road bridges is not required; at the same time, the survey’s results of the operated superstructures indicate the presence of problems associated with the insufficient endurance of these elements. The article presents comprehensive (qualitative and quantitative) comparative analysis results of the world’s existing approaches to testing the endurance of the venture elements. At the stage of qualitative analysis, the author considered methods of checking the endurance of elements in general according to the norms of 8 countries and regions (Russia, the European Union, the USA, Ukraine, Australia, Canada, Japan, China) and highlighted a basic set of methods for checking the endurance of the venture elements (Russia, the European Union, USA, Ukraine). The models of the basic set were subjected to a detailed qualitative analysis according to the criteria of the models used and the parameters included in them. The quantitative analysis of the selected basic set techniques, carried out in relation to the existing bridge, included an analysis of the effects of moving loads on the venture elements, direct elements verification using the considered methods, as well as the design damage comparison of the elements obtained by the Palmgren-Miner linear summation hypothesis. Based on the obtained values of design damage, the values of the use of endurance reserves were determined and analyzed for each of the considered methods and the conditional load model. Based on the results of the qualitative and quantitative analysis, the author draws conclusions based on the comparison of various methods and highlights the rational directions for improving the existing domestic methodology.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116657221","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 discusses the issues of the railway embankment operation crossing faults with upland movements at different angles. Examples of the engineering structures operation are given in this article: tunnels, bridges, roadbed, pipelines in conditions of tectonic activity. Existing regulatory documents recommend choosing a route with a bypass of the places where tectonic faults reach the ground’s surface. However, taking into account the existing fault-block structure of the ground’s crust, it is practically impossible to bypass the tectonic fault zones. The existing network of railways for the most part was laid without taking into account modern requirements norms. Therefore, it seems relevant to study the operation of both the operated and the projected railway track in the tectonic disturbances zones with upland movements. In this article, using the software and computing complex Midas GTS, designed for geotechnical calculations, a study of the railway embankment operation crossing at different angles in the horizontal plane faults with conditional upland movements of the fault block has been carried out. For this, a three-dimensional finite element model was created. The calculations used the Coulomb-Mohr elastoplastic soil work model. As a result, the deformations of the embankment’s main area were analyzed. The deformations components and their contribution to the overall value are considered in detail. Conclusions are made about the change in the longitudinal slope of the axis and the skew of the transverse profile of the main site. For the most deformed sections, normal and tangential stresses diagrams. The research results analysis made it possible to establish a number of characteristic regularities in the change in the embankment’s stress-strain state, depending on the angle between the track and the fault axes. The article is part of the author’s dissertation research
{"title":"Study of the railway embankment operation that crossing faults upland movements at different angles","authors":"S. Isaev","doi":"10.15862/04SATS121","DOIUrl":"https://doi.org/10.15862/04SATS121","url":null,"abstract":"The article discusses the issues of the railway embankment operation crossing faults with upland movements at different angles. Examples of the engineering structures operation are given in this article: tunnels, bridges, roadbed, pipelines in conditions of tectonic activity. Existing regulatory documents recommend choosing a route with a bypass of the places where tectonic faults reach the ground’s surface. However, taking into account the existing fault-block structure of the ground’s crust, it is practically impossible to bypass the tectonic fault zones. The existing network of railways for the most part was laid without taking into account modern requirements norms. Therefore, it seems relevant to study the operation of both the operated and the projected railway track in the tectonic disturbances zones with upland movements. In this article, using the software and computing complex Midas GTS, designed for geotechnical calculations, a study of the railway embankment operation crossing at different angles in the horizontal plane faults with conditional upland movements of the fault block has been carried out. For this, a three-dimensional finite element model was created. The calculations used the Coulomb-Mohr elastoplastic soil work model. As a result, the deformations of the embankment’s main area were analyzed. The deformations components and their contribution to the overall value are considered in detail. Conclusions are made about the change in the longitudinal slope of the axis and the skew of the transverse profile of the main site. For the most deformed sections, normal and tangential stresses diagrams. The research results analysis made it possible to establish a number of characteristic regularities in the change in the embankment’s stress-strain state, depending on the angle between the track and the fault axes. The article is part of the author’s dissertation research","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116112289","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}
Take into the account climate and environmental conditions of this region are necessary during modern road construction technologies introduction in the Republic of Sakha (Yakutia). This region’s climate and environmental conditions in many ways are identified as extreme. First of all, it should be noted that Yakutia is the coldest region of the Russian Federation, its territory is completely located in the permafrost zone. At the constructional materials testing center of the Pacific National University, were executed experimental studies to develop technological regulations for the modified bituminous binder manufacturing intended for paving the Lena highway (Yakutsk – Never). In this work, for the polymer-bitumen binder manufacturing, was used bitumen petroleum viscous for road building, grade BND 130/200. In the course of the research, the polymer-bitumen binders PBV 200 and PBV 300 with a brittle temperature not exceeding -35 °C and -40 °C with the thermoplastic elastomers SBS LG 502 (South Korea) and SBS R 30-00A (JSC «Voronezhsintezkauchuk») additives use the formula selecting problem were solved, as well as plasticizer – industrial oil I-40A. To optimize the composition of the binder and further improve its characteristics, it is proposed to use bitumen with increased content of maltene fractions and to include in its composition an adhesion additive of the amphoteric type DAD-1. The resulting polymer-bitumen binder is characterized by a wide performance range – an increased softening temperature and a low brittleness temperature, elasticity (ability to reversible deformations), high adhesion to various rocks. Achieving these goals will improve the asphalt concrete pavement quality and durability in difficult climatic conditions.
在萨哈共和国(雅库特)引进现代道路建设技术时，必须考虑到该地区的气候和环境条件。这个地区的气候和环境条件在很多方面都被认为是极端的。首先，应该指出的是，雅库特是俄罗斯联邦最冷的地区，其领土完全位于永久冻土带。在太平洋国立大学的建筑材料测试中心，进行了实验性研究，以制定用于铺列拿公路(雅库茨克-永远)的改性沥青粘合剂制造的技术法规。在本工作中，用于聚合物-沥青粘合剂的制造，使用沥青石油粘性筑路，等级为BND 130/200。在研究过程中，解决了脆性温度不超过-35℃和-40℃的聚合物-沥青粘结剂PBV 200和PBV 300与热塑性弹性体SBS LG 502(韩国)和SBS R 30-00A (JSC«Voronezhsintezkauchuk»)添加剂使用配方的选择问题，以及增塑剂工业油I-40A的选用问题。为了优化粘结剂的组成，进一步改善其性能，建议使用增加马氏烯组分含量的沥青，并在其组成中加入两性型粘结剂DAD-1。由此产生的聚合物-沥青粘合剂具有广泛的性能范围-软化温度升高，脆性温度低，弹性(可逆变形的能力)，对各种岩石的附着力高。实现这些目标将提高沥青混凝土路面的质量和在恶劣气候条件下的耐久性。
{"title":"Modified bituminous binders for road construction in the Republic of Sakha (Yakutia)","authors":"T. Lazareva, A. Parfenov","doi":"10.15862/09SATS420","DOIUrl":"https://doi.org/10.15862/09SATS420","url":null,"abstract":"Take into the account climate and environmental conditions of this region are necessary during modern road construction technologies introduction in the Republic of Sakha (Yakutia). This region’s climate and environmental conditions in many ways are identified as extreme. First of all, it should be noted that Yakutia is the coldest region of the Russian Federation, its territory is completely located in the permafrost zone. At the constructional materials testing center of the Pacific National University, were executed experimental studies to develop technological regulations for the modified bituminous binder manufacturing intended for paving the Lena highway (Yakutsk – Never).\u0000In this work, for the polymer-bitumen binder manufacturing, was used bitumen petroleum viscous for road building, grade BND 130/200. In the course of the research, the polymer-bitumen binders PBV 200 and PBV 300 with a brittle temperature not exceeding -35 °C and -40 °C with the thermoplastic elastomers SBS LG 502 (South Korea) and SBS R 30-00A (JSC «Voronezhsintezkauchuk») additives use the formula selecting problem were solved, as well as plasticizer – industrial oil I-40A. To optimize the composition of the binder and further improve its characteristics, it is proposed to use bitumen with increased content of maltene fractions and to include in its composition an adhesion additive of the amphoteric type DAD-1. The resulting polymer-bitumen binder is characterized by a wide performance range – an increased softening temperature and a low brittleness temperature, elasticity (ability to reversible deformations), high adhesion to various rocks. Achieving these goals will improve the asphalt concrete pavement quality and durability in difficult climatic conditions.","PeriodicalId":145434,"journal":{"name":"Russian journal of transport engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133663928","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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