Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.608
Yanhai Yang, Liang Yue, Ye Yang, Guanliang Chen
The road performance decay law of EACRM under freeze-thaw cycles was studied using laboratory tests on the macroscopic scale in order to comprehensively analyze the serious performance damage mechanism of emulsified asphalt cold recycled mixture (EACRM) in cold regions during the service period. The surface cracking behavior, internal void evolution characteristics, and asphalt mortar morphology damage of EACRM under freeze-thaw cycles were studied by means of digital speckle, industrial CT, and scanning electron microscope (SEM) on the mesoscopic and microscopic scale. The results show that along with the increase in the number of freeze-thaw cycles, the road performance of EACRM decreases significantly. The surface of EACRM obviously cracks, and the width and number of main cracks increase significantly. The fatigue times of the maximum horizontal strain in the whole field gradually decrease. Air voids and the average volume of meso-void visibly increase. The microcracks of cement-emulsified asphalt mortar constantly emerge at the interface. The serious damage of the “three-dimensional network structure” is the fundamental reason for the performance decay of EACRM in cold regions. The performance damage of EACRM in cold regions is aggravated by water seeping into voids from cracks. Eventually, EACRM shows serious freeze-thaw inflicted damage.
{"title":"Multi-Scale Decay Mechanism of Emulsified Asphalt Cold Recycled Mixture Under Freeze-Thaw","authors":"Yanhai Yang, Liang Yue, Ye Yang, Guanliang Chen","doi":"10.7250/bjrbe.2023-18.608","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.608","url":null,"abstract":"The road performance decay law of EACRM under freeze-thaw cycles was studied using laboratory tests on the macroscopic scale in order to comprehensively analyze the serious performance damage mechanism of emulsified asphalt cold recycled mixture (EACRM) in cold regions during the service period. The surface cracking behavior, internal void evolution characteristics, and asphalt mortar morphology damage of EACRM under freeze-thaw cycles were studied by means of digital speckle, industrial CT, and scanning electron microscope (SEM) on the mesoscopic and microscopic scale. The results show that along with the increase in the number of freeze-thaw cycles, the road performance of EACRM decreases significantly. The surface of EACRM obviously cracks, and the width and number of main cracks increase significantly. The fatigue times of the maximum horizontal strain in the whole field gradually decrease. Air voids and the average volume of meso-void visibly increase. The microcracks of cement-emulsified asphalt mortar constantly emerge at the interface. The serious damage of the “three-dimensional network structure” is the fundamental reason for the performance decay of EACRM in cold regions. The performance damage of EACRM in cold regions is aggravated by water seeping into voids from cracks. Eventually, EACRM shows serious freeze-thaw inflicted damage.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135719597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.611
Joanna Hydzik-Wiśniewska, Łukasz Ostrowski, Anna Wilk, Adrian Krajewski
The article presents the e valuation o f h ow suitable waste from the production of aggregates in quarries could be in earthwork using the example of screen-outs from Krosno sandstone. The waste, called screen-out, is characterised by an uncontrolled content of dust and clay fractions. Screen-outs have a relatively low bearing ratio (CBR not exceeding 20%) and a tendency to heave due to frost (SE <35). To check whether the geotechnical properties can be improved, mixtures with 2%, 5%, and 8% binders, such as lime, fly ash, and two road binders with lime, fly ash, and cement were prepared. The analysis was based on the results of the CBR and compressive strength tests. The use of mineral binders caused the value of the immediate CBR to increase compared to the screen-out itself from a dozen to as much as 50%. For a binder containing 20% Portland clinker, the CBR was about 60% after 4 days of saturation, while for a binder containing up to 50% Portland clinker, it was over 200%. The value of compressive strength after 28 days of maturing ranged from about 100 kPa to 1 MPa for all mixes tested. The lowest values were obtained for screen-outs activated with fly ash, and the highest for road binder with cement content of up to 50%.
{"title":"Screen-Out Stones Activated with Mineral Binders and Used as Material for Earth Construction","authors":"Joanna Hydzik-Wiśniewska, Łukasz Ostrowski, Anna Wilk, Adrian Krajewski","doi":"10.7250/bjrbe.2023-18.611","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.611","url":null,"abstract":"The article presents the e valuation o f h ow suitable waste from the production of aggregates in quarries could be in earthwork using the example of screen-outs from Krosno sandstone. The waste, called screen-out, is characterised by an uncontrolled content of dust and clay fractions. Screen-outs have a relatively low bearing ratio (CBR not exceeding 20%) and a tendency to heave due to frost (SE <35). To check whether the geotechnical properties can be improved, mixtures with 2%, 5%, and 8% binders, such as lime, fly ash, and two road binders with lime, fly ash, and cement were prepared. The analysis was based on the results of the CBR and compressive strength tests. The use of mineral binders caused the value of the immediate CBR to increase compared to the screen-out itself from a dozen to as much as 50%. For a binder containing 20% Portland clinker, the CBR was about 60% after 4 days of saturation, while for a binder containing up to 50% Portland clinker, it was over 200%. The value of compressive strength after 28 days of maturing ranged from about 100 kPa to 1 MPa for all mixes tested. The lowest values were obtained for screen-outs activated with fly ash, and the highest for road binder with cement content of up to 50%.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.609
Paulius Paplauskas, Audrius Vaitkus, Rūta Simanavičienė
Surveying the condition of the pavement is one of the most important processes in managing the road network. The information collected during these surveys allows for the calculation of the Pavement Condition Index, which is a derivative cumulative qualitative indicator that evaluates various pavement characteristics and defects. Deterioration modelling of these measured indicators and calculated indices is a critical element and its most accurate prediction brings the process of pavement management closer to a higher quality process by more efficiently allocating funds and repair work. Many different models – both extremely complex and simple – are used in the world to simulate the condition of individual pavement indicators. However, these models are developed based on the data of a certain country or region and are not suitable in another country due to different requirements for pavement structures and other reasons. In Lithuania, measurements of the quality indicators of road surfaces with new generation survey equipment have been carried out recently but the information stored in the databases about road sections is minimal, and it becomes difficult to adapt the models applied abroad due to the missing information. The aim of this study is to create pavement condition index prediction models by evaluating such quantitative and qualitative indicators as traffic loads, road surface unevenness, type of repair, pavement age, climatic zones, and pavement construction classes.
{"title":"Road Pavement Condition Index Deterioration Model for Network-Level Analysis of National Road Network Based on Pavement Condition Scanning Data","authors":"Paulius Paplauskas, Audrius Vaitkus, Rūta Simanavičienė","doi":"10.7250/bjrbe.2023-18.609","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.609","url":null,"abstract":"Surveying the condition of the pavement is one of the most important processes in managing the road network. The information collected during these surveys allows for the calculation of the Pavement Condition Index, which is a derivative cumulative qualitative indicator that evaluates various pavement characteristics and defects. Deterioration modelling of these measured indicators and calculated indices is a critical element and its most accurate prediction brings the process of pavement management closer to a higher quality process by more efficiently allocating funds and repair work. Many different models – both extremely complex and simple – are used in the world to simulate the condition of individual pavement indicators. However, these models are developed based on the data of a certain country or region and are not suitable in another country due to different requirements for pavement structures and other reasons. In Lithuania, measurements of the quality indicators of road surfaces with new generation survey equipment have been carried out recently but the information stored in the databases about road sections is minimal, and it becomes difficult to adapt the models applied abroad due to the missing information. The aim of this study is to create pavement condition index prediction models by evaluating such quantitative and qualitative indicators as traffic loads, road surface unevenness, type of repair, pavement age, climatic zones, and pavement construction classes.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135719596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.614
Andrzej Ambroziak, Maciej Malinowski
The structural analysis of an old steel riveted railway truss bridge located over the Maruska River on the Działdowo – Olsztyn, Poland railway line is performed in this paper to check its behaviour under today’s railway loads. The mechanical properties of construction steel extracted from the old steel bridge are investigated by tensile tests, impact tests through the Charpy pendulum impact V-notch, and an optical emission spectrometer. Structural analysis exhibits that the steel bridge requires proper structural bridge improvements to meet today’s load requirements in terms of bearing capacity and serviceability state. The paper begins with a wide survey of literature carried out on the investigation of steel riveted railway bridge subject matter. This paper can provide scientists, engineers, and designers with an experimental and structural basis in the field of old steel riveted railway truss bridge construction.
{"title":"Case Study of Old Steel Riveted Railway Truss Bridge: From Material Characterization to Structural Analysis","authors":"Andrzej Ambroziak, Maciej Malinowski","doi":"10.7250/bjrbe.2023-18.614","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.614","url":null,"abstract":"The structural analysis of an old steel riveted railway truss bridge located over the Maruska River on the Działdowo – Olsztyn, Poland railway line is performed in this paper to check its behaviour under today’s railway loads. The mechanical properties of construction steel extracted from the old steel bridge are investigated by tensile tests, impact tests through the Charpy pendulum impact V-notch, and an optical emission spectrometer. Structural analysis exhibits that the steel bridge requires proper structural bridge improvements to meet today’s load requirements in terms of bearing capacity and serviceability state. The paper begins with a wide survey of literature carried out on the investigation of steel riveted railway bridge subject matter. This paper can provide scientists, engineers, and designers with an experimental and structural basis in the field of old steel riveted railway truss bridge construction.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135719598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.615
Laura Gavėnienė, Donatas Čygas, Laura Jateikienė, Viktoras Vorobjovas, Vilma Jasiūnienė, Atis Zarinš
The speeding is a major road safety problem on the roads of Lithuania and many other countries. To reduce and control the speed of vehicles, engineering measures are installed on the roads of Lithuania and other countries – intelligent instantaneous and average speed enforcement systems, as well as many other engineering and structural speed reduction measures. The article presents good practices in the use of average speed enforcement systems, assessment of their effect on road safety. The article analyses the assessment results of the effect of the average speed enforcement systems installed on 25 sections of roads in Lithuania that have been operating for four years. Calculations of the effect factor of the installed average speed enforcement systems on road safety were performed using the before-and-after (B&A) method with a comparison group. Studies on the effect of application of speed control systems provide conditions for evaluating road safety, i.e., changes in road accidents linked to the effectiveness of implemented measures. The conclusions of the conducted study presented the calculations of the efficiency coefficients of the average speed enforcement systems on Lithuanian main and national roads. The analysis of the results of the conducted study allows stating that the installed average speed enforcement systems on 25 sections of Lithuanian roads increase overall road safety by 47%, reduce the number of collisions with animals by 80%, and the number of collisions with vehicles by 35%, as well as the number of other road accidents by 56%.
{"title":"An Assessment of The Effect of The Average Speed Enforcement Systems on Lithuanian Roads","authors":"Laura Gavėnienė, Donatas Čygas, Laura Jateikienė, Viktoras Vorobjovas, Vilma Jasiūnienė, Atis Zarinš","doi":"10.7250/bjrbe.2023-18.615","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.615","url":null,"abstract":"The speeding is a major road safety problem on the roads of Lithuania and many other countries. To reduce and control the speed of vehicles, engineering measures are installed on the roads of Lithuania and other countries – intelligent instantaneous and average speed enforcement systems, as well as many other engineering and structural speed reduction measures. The article presents good practices in the use of average speed enforcement systems, assessment of their effect on road safety. The article analyses the assessment results of the effect of the average speed enforcement systems installed on 25 sections of roads in Lithuania that have been operating for four years. Calculations of the effect factor of the installed average speed enforcement systems on road safety were performed using the before-and-after (B&A) method with a comparison group. Studies on the effect of application of speed control systems provide conditions for evaluating road safety, i.e., changes in road accidents linked to the effectiveness of implemented measures. The conclusions of the conducted study presented the calculations of the efficiency coefficients of the average speed enforcement systems on Lithuanian main and national roads. The analysis of the results of the conducted study allows stating that the installed average speed enforcement systems on 25 sections of Lithuanian roads increase overall road safety by 47%, reduce the number of collisions with animals by 80%, and the number of collisions with vehicles by 35%, as well as the number of other road accidents by 56%.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.612
Olli Asp, Anssi Laaksonen
The national calibration of Eurocode load model 1 (LM1) for road bridges was made by a calibration of the load effects of LM1 against the corresponding load effects of a former load model used in Finland. Due to the increased gross vehicle weights in legislation, a national calibration of LM1 was necessary and the stochastic simulation was needed. The aim of this study is to generate a traffic model together with a predictive model for simulation purposes by using and combining long-time monitoring data measured on a road network in different surveys. In this paper, the performance of the predictive model of increases in axle loads and gross vehicle weights is evaluated against short-term bridge weight in motion (BWIM) measurements. The results achieved with a simulation can be used to gain more information of statistical parameters and the evolution of load effects caused on bridges by road traffic in Finland. The simulation model presented in this study served as a basis for updated national calibration of load model LM1. The follow-up comparison between predictive model and traffic monitoring shows the suitability of the estimation of the evolution of traffic loads and also necessity of the raise of LM1.
{"title":"Traffic Load Model Calibration and Comparison to Evolving Traffic Loads In 2014–2018","authors":"Olli Asp, Anssi Laaksonen","doi":"10.7250/bjrbe.2023-18.612","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.612","url":null,"abstract":"The national calibration of Eurocode load model 1 (LM1) for road bridges was made by a calibration of the load effects of LM1 against the corresponding load effects of a former load model used in Finland. Due to the increased gross vehicle weights in legislation, a national calibration of LM1 was necessary and the stochastic simulation was needed. The aim of this study is to generate a traffic model together with a predictive model for simulation purposes by using and combining long-time monitoring data measured on a road network in different surveys. In this paper, the performance of the predictive model of increases in axle loads and gross vehicle weights is evaluated against short-term bridge weight in motion (BWIM) measurements. The results achieved with a simulation can be used to gain more information of statistical parameters and the evolution of load effects caused on bridges by road traffic in Finland. The simulation model presented in this study served as a basis for updated national calibration of load model LM1. The follow-up comparison between predictive model and traffic monitoring shows the suitability of the estimation of the evolution of traffic loads and also necessity of the raise of LM1.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.607
Oleksandr Rieznik, Shilin Yang, Andrii Bieliatynskyi, Meiyu Shao, Mingyang Ta
Statistics of road accidents show that even in the summer the number of accidents directly depends on weather conditions, and one such reason is aquaplaning in some parts of the road. Therefore, solving the issue of improving the road structure in such areas, while maintaining the regulatory strength, equality and coefficient of adhesion are relevant in road construction. The research allowed developing an improved mixture of porous asphalt mixture taking into account the physical-mechanical and operational properties. The construction of the road surface was also improved with the separation of the pavement layers, where porous asphalt mixture was used as the top layer, and the basalt canvas (impregnated) between the used construction levels was used. The mathematical calculation of the road was improved taking into account the physical phenomena occurring between the car and the road surface in the presence of water. The speed limits were calculated, and the thickness of the fluid layer was taken into account as well. The authors of the article also paid attention to the influence of road roughness on the speed limit.
{"title":"Research of Porous Asphalt Concrete Application on Highway Sections with The Increased Aquaplaning Danger Level","authors":"Oleksandr Rieznik, Shilin Yang, Andrii Bieliatynskyi, Meiyu Shao, Mingyang Ta","doi":"10.7250/bjrbe.2023-18.607","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.607","url":null,"abstract":"Statistics of road accidents show that even in the summer the number of accidents directly depends on weather conditions, and one such reason is aquaplaning in some parts of the road. Therefore, solving the issue of improving the road structure in such areas, while maintaining the regulatory strength, equality and coefficient of adhesion are relevant in road construction. The research allowed developing an improved mixture of porous asphalt mixture taking into account the physical-mechanical and operational properties. The construction of the road surface was also improved with the separation of the pavement layers, where porous asphalt mixture was used as the top layer, and the basalt canvas (impregnated) between the used construction levels was used. The mathematical calculation of the road was improved taking into account the physical phenomena occurring between the car and the road surface in the presence of water. The speed limits were calculated, and the thickness of the fluid layer was taken into account as well. The authors of the article also paid attention to the influence of road roughness on the speed limit.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.606
Mian Zhang, Xin Jiang, Yanjun Qiu
As a means of predicting the damage pattern and design life of asphalt pavement structures, the reliability of damage analysis is highly dependent on the calculation accuracy of the pavement mechanical responses under wheel load. The nonlinear analysis, on its part, can practically describe the stress dependence of the modulus of granular materials and fine-grained soils, so that the mechanical responses of the wheel-loaded asphalt pavement structure can be obtained more accurately. Therefore, the correct application of nonlinear analysis technology is essential to obtain reliable damage analysis results. For this reason, computer program KENLAYER was utilized to explore the effects of stress adjustment methods and core parameters of nonlinear iterative analysis on the damage analysis results. According to the calculation results, this paper explains the reasons why the stress adjustment Methods 2 and 3 are not applicable to the structural analysis of pavements containing nonlinear granular materials in the case of thin surface layers, illustrates the effects of improper selection of the adjustment methods and each iteration parameter on the dominant damage pattern, finds out the reasons for unreliable calculation results due to improper selection of the iteration parameters, and makes corresponding suggestions for carrying out damage analysis accurately.
{"title":"Influence of Nonlinear Analysis Technology on Damage Analysis of Asphalt Pavement Structure","authors":"Mian Zhang, Xin Jiang, Yanjun Qiu","doi":"10.7250/bjrbe.2023-18.606","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.606","url":null,"abstract":"As a means of predicting the damage pattern and design life of asphalt pavement structures, the reliability of damage analysis is highly dependent on the calculation accuracy of the pavement mechanical responses under wheel load. The nonlinear analysis, on its part, can practically describe the stress dependence of the modulus of granular materials and fine-grained soils, so that the mechanical responses of the wheel-loaded asphalt pavement structure can be obtained more accurately. Therefore, the correct application of nonlinear analysis technology is essential to obtain reliable damage analysis results. For this reason, computer program KENLAYER was utilized to explore the effects of stress adjustment methods and core parameters of nonlinear iterative analysis on the damage analysis results. According to the calculation results, this paper explains the reasons why the stress adjustment Methods 2 and 3 are not applicable to the structural analysis of pavements containing nonlinear granular materials in the case of thin surface layers, illustrates the effects of improper selection of the adjustment methods and each iteration parameter on the dominant damage pattern, finds out the reasons for unreliable calculation results due to improper selection of the iteration parameters, and makes corresponding suggestions for carrying out damage analysis accurately.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.613
Csaba Ágh
Track geometry measurements are widely used for describing track quality. However, derailments and track deterioration are caused by forces arising in vehicle-track system. This research focuses on two types of vehicle response. Firstly, the influence of the longitudinal level irregularities on the vertical wheel-rail forces was examined. Secondly, the correlation between the lateral axle box acceleration and the cross level irregularities was investigated. Track geometry and vehicle response data were acquired simultaneously by a track recording car, formed from a passenger car, at various speeds up to 130 km/h. Vehicle-track forces were calculated based on accelerometers mounted on the car body, bogies and axle boxes, considering mass and moment of inertia. Non-linear regressions resulted in vertical vehicle-track force estimation functions. It was proven that the use of second spatial derivatives of the longitudinal level gave a better estimation than the use of reference TQIs according to European Standard EN 13848-6. A linear relationship was found between the speed and standard deviation of vertical vehicle-track forces. On straight sections with constant speed, correlation coefficients of around 0.8 were found between second spatial derivatives of cross level and lateral axle box acceleration.
{"title":"Connection Between Track Geometry Quality and Dynamic Vehicle Response at Various Speeds","authors":"Csaba Ágh","doi":"10.7250/bjrbe.2023-18.613","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.613","url":null,"abstract":"Track geometry measurements are widely used for describing track quality. However, derailments and track deterioration are caused by forces arising in vehicle-track system. This research focuses on two types of vehicle response. Firstly, the influence of the longitudinal level irregularities on the vertical wheel-rail forces was examined. Secondly, the correlation between the lateral axle box acceleration and the cross level irregularities was investigated. Track geometry and vehicle response data were acquired simultaneously by a track recording car, formed from a passenger car, at various speeds up to 130 km/h. Vehicle-track forces were calculated based on accelerometers mounted on the car body, bogies and axle boxes, considering mass and moment of inertia. Non-linear regressions resulted in vertical vehicle-track force estimation functions. It was proven that the use of second spatial derivatives of the longitudinal level gave a better estimation than the use of reference TQIs according to European Standard EN 13848-6. A linear relationship was found between the speed and standard deviation of vertical vehicle-track forces. On straight sections with constant speed, correlation coefficients of around 0.8 were found between second spatial derivatives of cross level and lateral axle box acceleration.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-26DOI: 10.7250/bjrbe.2023-18.610
Gezim Hoxha, Mevlan Bixhaku, Ramadan Duraku
The treatment and analysis of accidents involving heavy transport vehicles and pedestrians include the identification and treatment of a certain number of factors that may differ from the cases of passenger vehicle-pedestrian accidents. The aim of this paper is to develop a new model with better performance for speed estimation and reconstruction of accidents involving heavy vehicles and pedestrians. In a large number of cases during the research, it was observed that the experts used the same models for passenger vehicles as for transport vehicles. Likewise, a number of factors that have an impact on heavy vehicle accidents with pedestrians are not included as factors that have an impact on other accidents. The newly developed model, which has better performance than other models, can help experts in the case of analysis, speed determination, and reconstruction of accidents involving heavy vehicles and pedestrians. The model describes more than 94% of the most influential factors in the model (R2 = 0.945). This model will provide a novel way to examine crashes involving heavy vehicles and pedestrians, generating highly precise results for speed calculation which can be used to recreate the technical aspects of the accident. Additionally, it will help specialists in the field when preparing their expert opinion, specifically when heavy vehicles and pedestrians are involved, by providing a model which is different from the standard approach and yields more reliable outcomes.
{"title":"Developing A New Model for Assessment of Heavy Vehicle-Pedestrian Collisions","authors":"Gezim Hoxha, Mevlan Bixhaku, Ramadan Duraku","doi":"10.7250/bjrbe.2023-18.610","DOIUrl":"https://doi.org/10.7250/bjrbe.2023-18.610","url":null,"abstract":"The treatment and analysis of accidents involving heavy transport vehicles and pedestrians include the identification and treatment of a certain number of factors that may differ from the cases of passenger vehicle-pedestrian accidents. The aim of this paper is to develop a new model with better performance for speed estimation and reconstruction of accidents involving heavy vehicles and pedestrians. In a large number of cases during the research, it was observed that the experts used the same models for passenger vehicles as for transport vehicles. Likewise, a number of factors that have an impact on heavy vehicle accidents with pedestrians are not included as factors that have an impact on other accidents. The newly developed model, which has better performance than other models, can help experts in the case of analysis, speed determination, and reconstruction of accidents involving heavy vehicles and pedestrians. The model describes more than 94% of the most influential factors in the model (R2 = 0.945). This model will provide a novel way to examine crashes involving heavy vehicles and pedestrians, generating highly precise results for speed calculation which can be used to recreate the technical aspects of the accident. Additionally, it will help specialists in the field when preparing their expert opinion, specifically when heavy vehicles and pedestrians are involved, by providing a model which is different from the standard approach and yields more reliable outcomes.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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