Young bicyclists in Montreal are taking voluntary risks such as bicycling without wearing helmet and braking system of bicycle although they are aware of the presence of danger. This article analyses the behaviour of young bicyclists taking voluntary risks. The university students in Montreal are considered as the case study since they are more risk takers and the bicycle is a favorite mode of transport among them. This study reveals that half of the respondents did not use helmets. They were also spontaneously taking a risk by high speeding, violating signals, bicycling in mixed traffic, ignoring protective equipment after dark, and avoiding the bicycle designated roads. They were taking voluntary risks based on their attitude, subjective norm and perceived behavioural control. They did not perceive the severity of risks since they experienced relevant and unremarkable minor injuries. The attractiveness of risk and accomplishing the risk activities encouraged the young bicyclists to take voluntary risks repeatedly. Increasing feelings of vulnerability among young bicyclists reduce voluntary risks taking attitude and physical and psychological sufferings of the victims of bicycle-related accidents. Findings of this study suggest that the City of Montreal as well as other cities consider the behaviour of bicyclists particularly the young people to avoid bicycle-related accidents along with other physical measures.
{"title":"VOLUNTARY RISK TAKING BY YOUNG BICYCLISTS: A CASE STUDY OF UNIVERSITY STUDENTS AT MONTREAL","authors":"S. Amin","doi":"10.3846/BJRBE.2017.32","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.32","url":null,"abstract":"Young bicyclists in Montreal are taking voluntary risks such as bicycling without wearing helmet and braking system of bicycle although they are aware of the presence of danger. This article analyses the behaviour of young bicyclists taking voluntary risks. The university students in Montreal are considered as the case study since they are more risk takers and the bicycle is a favorite mode of transport among them. This study reveals that half of the respondents did not use helmets. They were also spontaneously taking a risk by high speeding, violating signals, bicycling in mixed traffic, ignoring protective equipment after dark, and avoiding the bicycle designated roads. They were taking voluntary risks based on their attitude, subjective norm and perceived behavioural control. They did not perceive the severity of risks since they experienced relevant and unremarkable minor injuries. The attractiveness of risk and accomplishing the risk activities encouraged the young bicyclists to take voluntary risks repeatedly. Increasing feelings of vulnerability among young bicyclists reduce voluntary risks taking attitude and physical and psychological sufferings of the victims of bicycle-related accidents. Findings of this study suggest that the City of Montreal as well as other cities consider the behaviour of bicyclists particularly the young people to avoid bicycle-related accidents along with other physical measures.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"258-263"},"PeriodicalIF":1.1,"publicationDate":"2017-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42562403","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}
Vytautas Dumbliauskas, Vytautas Grigonis, J. Vitkienė
Most of the Lithuanian cities try to achieve public transport priority by the provision of special dedicated public transport lanes. However, the possible priority measures at signalised intersections receive less attention. This paper explains common signal control strategies applied at isolated intersections in the cities around the world and estimated their effects on the travel times of both, public transport and general traffic. The analysis employs well recognised PTV VISSIM simulation environment and VisVAP graphical programming interface to implement and test priority measures under question. The results indicate that priority actions significantly reduce public transport delays up to 60%, without high adverse impact on general traffic delays.
{"title":"Estimating the Effects of Public Transport Priority Measures at Signal Controlled Intersections","authors":"Vytautas Dumbliauskas, Vytautas Grigonis, J. Vitkienė","doi":"10.3846/BJRBE.2017.23","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.23","url":null,"abstract":"Most of the Lithuanian cities try to achieve public transport priority by the provision of special dedicated public transport lanes. However, the possible priority measures at signalised intersections receive less attention. This paper explains common signal control strategies applied at isolated intersections in the cities around the world and estimated their effects on the travel times of both, public transport and general traffic. The analysis employs well recognised PTV VISSIM simulation environment and VisVAP graphical programming interface to implement and test priority measures under question. The results indicate that priority actions significantly reduce public transport delays up to 60%, without high adverse impact on general traffic delays.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"187-192"},"PeriodicalIF":1.1,"publicationDate":"2017-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49326851","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}
V. Šaulys, Oksana Survilė, M. Klimašauskas, L. Bagdžiūnaitė-Litvinaitienė, A. Litvinaitis, Rasa Stankevičienė, Aja Tumavičė
The relevance of research on removing surface water from the drained areas has increased along with a rising number of drainage systems. A large part of inlets for surface water are installed in the ditches of road safety zones and / or terrain drops in safety zones where flowing surface water accumulates. The practice of constructing and rebuilding roads in Lithuania shows that each new route of the road section most frequently passes through the drained area and redistributes runoff characteristics of that sector. Each subgrade passing through the watercourse of surface water is a local dam for surface runoff. The surface water that has accumulated in road safety zones have to be drained to avoid damage to road structures and from the flood in the drained roadside areas. The article discusses the efficiency of hydro technical measures such as inlets for surface water in the mining area and highlights the specificities of hydraulic calculations when the complete drainage system for surface water Inlet–Water Drainage Line is integrally assessed. The paper also proposes a methodology for the hydraulic calculations of the system Inlet–Water Drainage Line . The article examines the condition of water inlets having the F-5 or PN-42 structure. The findings of the research carried out in 2017 demonstrate that only 15.3% of inlets for surface water were completely clean, 45.2% of the inlets were found fully contaminated and 39.5% of those were partially silted up. Thus, a clear upward trend towards polluting the cross-sectional areas of inlets for surface water with soil and grass root plants and a strong downward trend towards clean cross-sectional areas of inlets for surface water are observed. 22.6% of inlets for surface water were found damaged by farmers using tillage machinery.
{"title":"Assessing the Hydraulic Conductivity of Open Drainage for Surface Water in Road Safety Zones","authors":"V. Šaulys, Oksana Survilė, M. Klimašauskas, L. Bagdžiūnaitė-Litvinaitienė, A. Litvinaitis, Rasa Stankevičienė, Aja Tumavičė","doi":"10.3846/BJRBE.2017.21","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.21","url":null,"abstract":"The relevance of research on removing surface water from the drained areas has increased along with a rising number of drainage systems. A large part of inlets for surface water are installed in the ditches of road safety zones and / or terrain drops in safety zones where flowing surface water accumulates. The practice of constructing and rebuilding roads in Lithuania shows that each new route of the road section most frequently passes through the drained area and redistributes runoff characteristics of that sector. Each subgrade passing through the watercourse of surface water is a local dam for surface runoff. The surface water that has accumulated in road safety zones have to be drained to avoid damage to road structures and from the flood in the drained roadside areas. The article discusses the efficiency of hydro technical measures such as inlets for surface water in the mining area and highlights the specificities of hydraulic calculations when the complete drainage system for surface water Inlet–Water Drainage Line is integrally assessed. The paper also proposes a methodology for the hydraulic calculations of the system Inlet–Water Drainage Line . The article examines the condition of water inlets having the F-5 or PN-42 structure. The findings of the research carried out in 2017 demonstrate that only 15.3% of inlets for surface water were completely clean, 45.2% of the inlets were found fully contaminated and 39.5% of those were partially silted up. Thus, a clear upward trend towards polluting the cross-sectional areas of inlets for surface water with soil and grass root plants and a strong downward trend towards clean cross-sectional areas of inlets for surface water are observed. 22.6% of inlets for surface water were found damaged by farmers using tillage machinery.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"174-180"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42523969","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}
One of the most significant factors affecting road safety is human. Estonia has improved road safety dramatically since its re-independence in 1991, and among the other reasons, this has happened due to changes in behaviour of road users. Likely, at the same time, there have been annual studies conducted, aimed at measuring specific indicators connected to compliance with road traffic law. As a result, one gets long-term trends in such indicators as compliance with traffic signals, usage of seat belts, yielding to pedestrians at uncontrolled crossings. This paper aims to describe Estonian traffic behaviour studies, analysing their results and pointing out actual problems in traffic behaviour. According to the results of studies, all aspects of traffic behaviour showed positive trends, but these trends are different. Certain indicators such as usage of seat belts have changed dramatically, while others like compliance with traffic signals showed only moderate changes. The foremost problem in traffic behaviour is found out to be ignorance to yield at uncontrolled pedestrian crossings. It is certainly one of the issues to deal with in the context of achieving Estonian strategic goals in road safety.
{"title":"Estonian Traffic Behaviour Monitoring Studies 2001–2016: Overview and Results","authors":"Juri Ess, D. Antov","doi":"10.3846/BJRBE.2017.20","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.20","url":null,"abstract":"One of the most significant factors affecting road safety is human. Estonia has improved road safety dramatically since its re-independence in 1991, and among the other reasons, this has happened due to changes in behaviour of road users. Likely, at the same time, there have been annual studies conducted, aimed at measuring specific indicators connected to compliance with road traffic law. As a result, one gets long-term trends in such indicators as compliance with traffic signals, usage of seat belts, yielding to pedestrians at uncontrolled crossings. This paper aims to describe Estonian traffic behaviour studies, analysing their results and pointing out actual problems in traffic behaviour. According to the results of studies, all aspects of traffic behaviour showed positive trends, but these trends are different. Certain indicators such as usage of seat belts have changed dramatically, while others like compliance with traffic signals showed only moderate changes. The foremost problem in traffic behaviour is found out to be ignorance to yield at uncontrolled pedestrian crossings. It is certainly one of the issues to deal with in the context of achieving Estonian strategic goals in road safety.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"167-173"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41459216","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}
J. Chalmovský, Jan Štefaňák, L. Míča, Z. Kala, Š. Skuodis, A. Norkus, D. Žilionienė
The paper presents an application of statistical and numerical methods for the determination of the force-displacement curves and that of pullout capacity of prestressed grouted ground anchors installed in Miocene clay. A regression analysis of data from a database of acceptance test records for ground anchors to create has been performed, the force-displacement curve of the tested anchor corresponding to the range of loads applied for acceptance tests has been created. A linear regression model, employing the weighted least squares method and robust standard errors techniques were concluded to serve as a reliable statistical method suitable for achieving this goal. The discovered linear regression dependence then served as a lower control limit for the displacement values calculated at the anchor head applying the numerical model. A finite element model has been created to predict the behaviour of ground anchors being installed in fine-grained soils. The developed numerical model that employs Mohr-Coulomb strength criterion constitutive model evaluates the influence of high-pressure grouting by development additional radial stresses and that of an increment of fixed length diameter.
{"title":"Statistical-Numerical Analysis for Pullout Tests of Ground Anchors","authors":"J. Chalmovský, Jan Štefaňák, L. Míča, Z. Kala, Š. Skuodis, A. Norkus, D. Žilionienė","doi":"10.3846/BJRBE.2017.17","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.17","url":null,"abstract":"The paper presents an application of statistical and numerical methods for the determination of the force-displacement curves and that of pullout capacity of prestressed grouted ground anchors installed in Miocene clay. A regression analysis of data from a database of acceptance test records for ground anchors to create has been performed, the force-displacement curve of the tested anchor corresponding to the range of loads applied for acceptance tests has been created. A linear regression model, employing the weighted least squares method and robust standard errors techniques were concluded to serve as a reliable statistical method suitable for achieving this goal. The discovered linear regression dependence then served as a lower control limit for the displacement values calculated at the anchor head applying the numerical model. A finite element model has been created to predict the behaviour of ground anchors being installed in fine-grained soils. The developed numerical model that employs Mohr-Coulomb strength criterion constitutive model evaluates the influence of high-pressure grouting by development additional radial stresses and that of an increment of fixed length diameter.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"145-153"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47671614","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}
Vaidas Ramūnas, A. Vaitkus, Alfredas Laurinavičius, D. Čygas, A. Šiukščius
As the railway lifespan is the main criterion for selection of the aggregate for ballast and for planning the maintenance of the railroad, it is important to define the relationship between the particle load resistant characteristics and a lifetime of ballast in structure. Assessment of the quality of the ballast aggregate particles under dynamic and static loading reflect both, the toughness and hardness, and these are identified with the Los Angeles Abrasion and Micro-Deval Abrasion values. The model formerly developed by Canadian Pacific Railroads was adapted to predict possible loads expressed in cumulated tonnes. Different ballast aggregate mixtures were tested in the laboratory including dolomite and granite. Calculated potential gross tonnage (expressed in Million Gross Tonnes) of the railway per lifetime for each different aggregate type presented. The outcome of this research is established classification system of railway ballast aggregate and defined Los Angeles Abrasion and Micro-Deval Abrasion values of aggregate dependently on required lifetime.
{"title":"Prediction of Lifespan of Railway Ballast Aggregate According to Mechanical Properties of it","authors":"Vaidas Ramūnas, A. Vaitkus, Alfredas Laurinavičius, D. Čygas, A. Šiukščius","doi":"10.3846/BJRBE.2017.25","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.25","url":null,"abstract":"As the railway lifespan is the main criterion for selection of the aggregate for ballast and for planning the maintenance of the railroad, it is important to define the relationship between the particle load resistant characteristics and a lifetime of ballast in structure. Assessment of the quality of the ballast aggregate particles under dynamic and static loading reflect both, the toughness and hardness, and these are identified with the Los Angeles Abrasion and Micro-Deval Abrasion values. The model formerly developed by Canadian Pacific Railroads was adapted to predict possible loads expressed in cumulated tonnes. Different ballast aggregate mixtures were tested in the laboratory including dolomite and granite. Calculated potential gross tonnage (expressed in Million Gross Tonnes) of the railway per lifetime for each different aggregate type presented. The outcome of this research is established classification system of railway ballast aggregate and defined Los Angeles Abrasion and Micro-Deval Abrasion values of aggregate dependently on required lifetime.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"203-209"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47908961","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}
The road safety development in East-European countries follows in general the trends of the western countries, even though there is a time lag. The fatality numbers are decreasing, though the improvements for the vulnerable road users are less impressive compared to other road user categories. The traditional road safety analysis based on accident history has many limitations related to accident under-reporting, low and random accident counts at individual sites and lack of details in the police or hospital reports. The surrogate safety methods are based on observation of other- than-accident occurrences that still have a strong relation to safety in traffic. Such methods are often more efficient (and pro-active) for safety assessments. The paper reviews the current status of the surrogate safety analysis methods, the challenges, and opportunities related to modern urban traffic conditions and the emerging technologies for more efficient data collection. The method is put in the context of the East-European countries to see how it contribute to the on-going road safety work and a better understanding of accidents risk factors necessary for producing effective safety counter-measures. (Less)
{"title":"Perspectives for surrogate safety studies in east-European countries","authors":"R. Ušpalytė-Vitkūnienė, A. Laureshyn","doi":"10.3846/BJRBE.2017.19","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.19","url":null,"abstract":"The road safety development in East-European countries follows in general the trends of the western countries, even though there is a time lag. The fatality numbers are decreasing, though the improvements for the vulnerable road users are less impressive compared to other road user categories. The traditional road safety analysis based on accident history has many limitations related to accident under-reporting, low and random accident counts at individual sites and lack of details in the police or hospital reports. The surrogate safety methods are based on observation of other- than-accident occurrences that still have a strong relation to safety in traffic. Such methods are often more efficient (and pro-active) for safety assessments. The paper reviews the current status of the surrogate safety analysis methods, the challenges, and opportunities related to modern urban traffic conditions and the emerging technologies for more efficient data collection. The method is put in the context of the East-European countries to see how it contribute to the on-going road safety work and a better understanding of accidents risk factors necessary for producing effective safety counter-measures. (Less)","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"161-166"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42355096","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}
Two hybrid model updating methods by integration of Gaussian mutation particle swarm optimization method, Latin Hypercube Sampling technique and meta models of Kriging and Back-Propagation Neural Network respectively were proposed, and the methods make the convergence speed of the model updating process faster and the Finite Element Model more adequate. Through the application of the hybrid methods to model updating process of a self-anchored suspension bridge in-service with extra-width, which showed great necessity considering the ambient vibration test results, the comparison of the two proposed methods was made. The results indicate that frequency differences between test and modified model were narrowed compared to results between test and original model after model updating using both methods as all the values are less than 6%, which is 25%−40% initially. Furthermore, the Model Assurance Criteria increase a little illustrating that more agreeable mode shapes are obtained as all of the Model Assurance Criteria are over 0.86. The particular advancements indicate that a relatively more adequate Finite Element Model is yielded with high efficiency without losing accuracy by both methods. However, the comparison among the two hybrid methods shows that the one with Back-Propagation Neural Network meta model is better than the one with Kriging meta model as the frequency differences of the former are mostly under 5%, but the latter ones are not. Furthermore, the former has higher efficiency than the other as the convergence speed of the former is faster. Thus, the hybrid method, within Gaussian mutation particle swarm optimization method and Back-Propagation Neural Network meta model, is more suitable for model updating of engineering applications with large-scale, multi-dimensional parameter structures involving implicit performance functions.
{"title":"Comparison of Hybrid Methods with Different Meta Model Used in Bridge Model-Updating","authors":"Zhiyuan Xia, Ai-qun Li, Jian-hui Li, Maojun Duan","doi":"10.3846/BJRBE.2017.24","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.24","url":null,"abstract":"Two hybrid model updating methods by integration of Gaussian mutation particle swarm optimization method, Latin Hypercube Sampling technique and meta models of Kriging and Back-Propagation Neural Network respectively were proposed, and the methods make the convergence speed of the model updating process faster and the Finite Element Model more adequate. Through the application of the hybrid methods to model updating process of a self-anchored suspension bridge in-service with extra-width, which showed great necessity considering the ambient vibration test results, the comparison of the two proposed methods was made. The results indicate that frequency differences between test and modified model were narrowed compared to results between test and original model after model updating using both methods as all the values are less than 6%, which is 25%−40% initially. Furthermore, the Model Assurance Criteria increase a little illustrating that more agreeable mode shapes are obtained as all of the Model Assurance Criteria are over 0.86. The particular advancements indicate that a relatively more adequate Finite Element Model is yielded with high efficiency without losing accuracy by both methods. However, the comparison among the two hybrid methods shows that the one with Back-Propagation Neural Network meta model is better than the one with Kriging meta model as the frequency differences of the former are mostly under 5%, but the latter ones are not. Furthermore, the former has higher efficiency than the other as the convergence speed of the former is faster. Thus, the hybrid method, within Gaussian mutation particle swarm optimization method and Back-Propagation Neural Network meta model, is more suitable for model updating of engineering applications with large-scale, multi-dimensional parameter structures involving implicit performance functions.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"193-202"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44720923","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}
A. Zofka, Maciej Maliszewski, E. Zofka, M. Paliukaite, L. Žalimienė
Geogrid materials applied within asphalt layers defer or prevent the occurrence of reflective cracking. The contribution of this work significantly adds to extending pavement serviceability and improving benefit/cost analysis. Since 1970s many studies have demonstrated the benefits of geogrid reinforcement in asphalt pavements, but this knowledge did not translate to their extensive usage in the actual construction practice. Among potential reasons are higher initial costs, lack of in-depth understanding of working mechanism within adjacent asphalt layers and lack of commonly standard design procedures. This paper presents a recent study, which investigated the effect of geogrid reinforcement on asphalt mixture specimens. Two types of laboratory experiments were conducted, namely monotonic (strength and fracture) testing and cyclic (fatigue and modulus) testing. The results demonstrated a significant strengthening contribution of geogrid, which was observed regarding fracture energy results and terminal deflections in the fatigue testing. This paper also presents a short example connecting pavement deflections with the allowable axle loading (also known as fatigue life) to demonstrate the practical implications of geogrid reinforcement. The undertaken analysis shows the reduction of pavement deflections due to the geogrid application, which potentially leads to a significant extension of pavement fatigue life. Paper concludes with several recommendations for further work in the area of geogrid reinforcement.
{"title":"Geogrid Reinforcement of Asphalt Pavements","authors":"A. Zofka, Maciej Maliszewski, E. Zofka, M. Paliukaite, L. Žalimienė","doi":"10.3846/BJRBE.2017.22","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.22","url":null,"abstract":"Geogrid materials applied within asphalt layers defer or prevent the occurrence of reflective cracking. The contribution of this work significantly adds to extending pavement serviceability and improving benefit/cost analysis. Since 1970s many studies have demonstrated the benefits of geogrid reinforcement in asphalt pavements, but this knowledge did not translate to their extensive usage in the actual construction practice. Among potential reasons are higher initial costs, lack of in-depth understanding of working mechanism within adjacent asphalt layers and lack of commonly standard design procedures. This paper presents a recent study, which investigated the effect of geogrid reinforcement on asphalt mixture specimens. Two types of laboratory experiments were conducted, namely monotonic (strength and fracture) testing and cyclic (fatigue and modulus) testing. The results demonstrated a significant strengthening contribution of geogrid, which was observed regarding fracture energy results and terminal deflections in the fatigue testing. This paper also presents a short example connecting pavement deflections with the allowable axle loading (also known as fatigue life) to demonstrate the practical implications of geogrid reinforcement. The undertaken analysis shows the reduction of pavement deflections due to the geogrid application, which potentially leads to a significant extension of pavement fatigue life. Paper concludes with several recommendations for further work in the area of geogrid reinforcement.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"181-186"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42842641","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}
For road infrastructures, the concepts of sustainability and resilience are becoming more and more relevant. The sustainability is closely linked with the concept of development that meets the needs of the present without compromising the ability of future generations to meet their own needs. The resilience is usually connected with the occurrence of extreme events or unusual disturbances (earthquake, landslide, floods) during the life cycle of infrastructures and refers to their ability of recover the previous functionality. Usually, the two concepts that account for two desired qualities of the infrastructures are applied following separate approaches. Better choices in road design, maintenance and rehabilitation should lead to an improvement of both qualities. On the other hand, an in deep analysis of the sustainability and resilience demonstrates a significant number of similar characteristics. In the light of the above premises, in the present paper, the suitability of an integrated approach in the choice of the rehabilitation alternatives after an extreme event is evaluated. A method to assess the sustainability, based on life cycle costs, and to estimate the resilience is setup. It resulted that an integrated perspective can be pursued and both resilience and sustainability allow addressing an appropriate amount of technical, economic and environmental/social issues and can lead to identifying the most efficient solution of rehabilitation.
{"title":"Sustainability and Resilience in the Rehabilitation of Road Infrastructures After an Extreme Event: An Integrated Approach","authors":"M. Giunta","doi":"10.3846/BJRBE.2017.18","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.18","url":null,"abstract":"For road infrastructures, the concepts of sustainability and resilience are becoming more and more relevant. The sustainability is closely linked with the concept of development that meets the needs of the present without compromising the ability of future generations to meet their own needs. The resilience is usually connected with the occurrence of extreme events or unusual disturbances (earthquake, landslide, floods) during the life cycle of infrastructures and refers to their ability of recover the previous functionality. Usually, the two concepts that account for two desired qualities of the infrastructures are applied following separate approaches. Better choices in road design, maintenance and rehabilitation should lead to an improvement of both qualities. On the other hand, an in deep analysis of the sustainability and resilience demonstrates a significant number of similar characteristics. In the light of the above premises, in the present paper, the suitability of an integrated approach in the choice of the rehabilitation alternatives after an extreme event is evaluated. A method to assess the sustainability, based on life cycle costs, and to estimate the resilience is setup. It resulted that an integrated perspective can be pursued and both resilience and sustainability allow addressing an appropriate amount of technical, economic and environmental/social issues and can lead to identifying the most efficient solution of rehabilitation.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"154-160"},"PeriodicalIF":1.1,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41605142","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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