A. Kilikevičius, D. Bacinskas, M. Jurevičius, Kristina Kilikevičienė, A. Fursenko, J. Jakaitis, Eligijus Toločka
Paper presents dynamic field test and analysis results of a three span railway steel continuous truss bridge over river Neris in Jonava. Bridge was originally constructed in 1914. In the period of the World War II and afterwards the bridge was many time destroyed by German and Soviet armies. In 1948 the new railway bridge was constructed. Object of the present paper is to evaluate dynamic behaviour of the railway bridge after 67 years in service. Experimental dynamic analysis was divided into resonance-vibration, forced-vibration and free vibration studies. Resonance-vibrations of the bridge were excited by separate actions of shock loading and standard locomotive 2M62. Forced-vibrations were measured under the action of locomotive 2M62. Additionally, free vibration tests under passage of freight and passenger trains have been carried out. Structural dynamic response of the bridge was analysed using Bruel & Kjaer LAN XI dynamic test system and software. As a result, main dynamic parameters of the bridge were obtained. The main results include: mode shapes, frequencies of natural and forced vibrations, damping ratios, maximum amplitudes of accelerations, dynamic displacements. The obtained values were compared to the requirements of different design codes. Based on the achieved results concluding remarks and recommendations regarding the condition of the bridge after long-term period in service were presented.
{"title":"Field testing and dynamic analysis of old continuous truss steel bridge","authors":"A. Kilikevičius, D. Bacinskas, M. Jurevičius, Kristina Kilikevičienė, A. Fursenko, J. Jakaitis, Eligijus Toločka","doi":"10.3846/BJRBE.2018.394","DOIUrl":"https://doi.org/10.3846/BJRBE.2018.394","url":null,"abstract":"Paper presents dynamic field test and analysis results of a three span railway steel continuous truss bridge over river Neris in Jonava. Bridge was originally constructed in 1914. In the period of the World War II and afterwards the bridge was many time destroyed by German and Soviet armies. In 1948 the new railway bridge was constructed. Object of the present paper is to evaluate dynamic behaviour of the railway bridge after 67 years in service. Experimental dynamic analysis was divided into resonance-vibration, forced-vibration and free vibration studies. Resonance-vibrations of the bridge were excited by separate actions of shock loading and standard locomotive 2M62. Forced-vibrations were measured under the action of locomotive 2M62. Additionally, free vibration tests under passage of freight and passenger trains have been carried out. Structural dynamic response of the bridge was analysed using Bruel & Kjaer LAN XI dynamic test system and software. As a result, main dynamic parameters of the bridge were obtained. The main results include: mode shapes, frequencies of natural and forced vibrations, damping ratios, maximum amplitudes of accelerations, dynamic displacements. The obtained values were compared to the requirements of different design codes. Based on the achieved results concluding remarks and recommendations regarding the condition of the bridge after long-term period in service were presented.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"13 1","pages":"54-66"},"PeriodicalIF":1.1,"publicationDate":"2018-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44620140","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}
Extremely large trucks with a weight exceeding the standard require a permit before they are allowed to cross the bridges of a specific route. For the purpose of safety, an escort is often employed to maintain a distance between vehicles and to ensure that the bridge load remain below the allowed maximum. Given that the speed of these large vehicles is quite slow and that the amplitude of vibrations normally declines when the vehicle mass is large, a minor dynamic amplification of the bridge response is expected. However, some of these large trucks have a unique feature characterized by “multiple equally-spaced axles”, something that is uncommon in normal vehicle. The application of axle forces at equal intervals can dynamically excite bridges to a considerable extent, even at low speeds. These “critical” low speeds are estimated a priori from the axle spacing of the truck and the main frequency of vibration of the bridge. This paper demonstrates that when the “critical” speed is unavoidable, a relatively high dynamic allowance must be added to static calculations before granting a permit to a long heavy vehicle.
{"title":"Dynamic impact of heavy long vehicles with equally spaced axles on short-span highway bridges","authors":"O. Mohammed, Arturo González, D. Cantero","doi":"10.3846/BJRBE.2018.382","DOIUrl":"https://doi.org/10.3846/BJRBE.2018.382","url":null,"abstract":"Extremely large trucks with a weight exceeding the standard require a permit before they are allowed to cross the bridges of a specific route. For the purpose of safety, an escort is often employed to maintain a distance between vehicles and to ensure that the bridge load remain below the allowed maximum. Given that the speed of these large vehicles is quite slow and that the amplitude of vibrations normally declines when the vehicle mass is large, a minor dynamic amplification of the bridge response is expected. However, some of these large trucks have a unique feature characterized by “multiple equally-spaced axles”, something that is uncommon in normal vehicle. The application of axle forces at equal intervals can dynamically excite bridges to a considerable extent, even at low speeds. These “critical” low speeds are estimated a priori from the axle spacing of the truck and the main frequency of vibration of the bridge. This paper demonstrates that when the “critical” speed is unavoidable, a relatively high dynamic allowance must be added to static calculations before granting a permit to a long heavy vehicle.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"13 1","pages":"1-13"},"PeriodicalIF":1.1,"publicationDate":"2018-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42622093","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 paper presents the analysis of the monitoring system of the embankment supported on concrete columns and overlaid by a load transfer platform with the embedded steel grid. This field investigation was to study the complex interaction between the columns, the load transfer platform layer, and steel grid via in situ measurements during erection and live loading of the embankment. The study was focused on the behaviour of steel grid and the behaviour of the outer rows of columns since there are limited reference data available for this problem. The system was designed to inform the engineers about the condition of the embankment at every stage of construction and during standard operation of the road. The measurements brought the information on strain variations of steel grid, concrete columns, and structural settlement and provided necessary evidence for the embankment numerical model validation.
{"title":"Monitoring System of the Road Embankment","authors":"M. Miśkiewicz, B. Meronk, T. Brzozowski, K. Wilde","doi":"10.3846/BJRBE.2017.27","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.27","url":null,"abstract":"The paper presents the analysis of the monitoring system of the embankment supported on concrete columns and overlaid by a load transfer platform with the embedded steel grid. This field investigation was to study the complex interaction between the columns, the load transfer platform layer, and steel grid via in situ measurements during erection and live loading of the embankment. The study was focused on the behaviour of steel grid and the behaviour of the outer rows of columns since there are limited reference data available for this problem. The system was designed to inform the engineers about the condition of the embankment at every stage of construction and during standard operation of the road. The measurements brought the information on strain variations of steel grid, concrete columns, and structural settlement and provided necessary evidence for the embankment numerical model validation.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"3 1","pages":"218-224"},"PeriodicalIF":1.1,"publicationDate":"2017-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69997546","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. Goremikins, D. Serdjuks, K. Buka-Vaivade, L. Pakrastins, N. Vatin
Cable truss usage allows developing bridges with reduced requirements for girder stiffness, where overall bridge rigidity is ensured by prestressing of the stabilization cable. The advantages of prestressed suspension trusses to provide required stiffness without massive stiffness girders and the ability of cross-laminated timber to behave in both directions are combined in the analysed structure. Prestressed cable truss with coincident (unclear meaning, difficult to translate) in the centre point of the span main and stabilization cables and vertical suspenders only was considered as the main load carrying system in the considered structure of suspension bridge. Two numerical models evaluated influence of cross-laminated timber deck on the behaviour of prestressed cable truss. Two physical models of the structure with the span equal to 2 m were developed for verification of the numerical models. The first physical model was developed for the case, when panels of the deck are placed without clearances and behaving in the longitudinal direction in compression so as in the transversal direction in bending. The second physical model was developed for the case when panels of the deck are placed with clearances and are behaving in the transverse direction in bending only. The dependences of maximum vertical displacements and horizontal support reaction of the cable truss on the intensity of vertical load in cases of symmetric and unsymmetrical loading were obtained for both physical models. Possibility to decrease the cable truss materials consumption by 17% by taking into account combined work of prestressed cable trusses and cross-laminated timber panels was stated.
{"title":"Prediction of Behaviour of Prestressed Suspension Bridge with Timber Deck Panels","authors":"V. Goremikins, D. Serdjuks, K. Buka-Vaivade, L. Pakrastins, N. Vatin","doi":"10.3846/BJRBE.2017.29","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.29","url":null,"abstract":"Cable truss usage allows developing bridges with reduced requirements for girder stiffness, where overall bridge rigidity is ensured by prestressing of the stabilization cable. The advantages of prestressed suspension trusses to provide required stiffness without massive stiffness girders and the ability of cross-laminated timber to behave in both directions are combined in the analysed structure. Prestressed cable truss with coincident (unclear meaning, difficult to translate) in the centre point of the span main and stabilization cables and vertical suspenders only was considered as the main load carrying system in the considered structure of suspension bridge. Two numerical models evaluated influence of cross-laminated timber deck on the behaviour of prestressed cable truss. Two physical models of the structure with the span equal to 2 m were developed for verification of the numerical models. The first physical model was developed for the case, when panels of the deck are placed without clearances and behaving in the longitudinal direction in compression so as in the transversal direction in bending. The second physical model was developed for the case when panels of the deck are placed with clearances and are behaving in the transverse direction in bending only. The dependences of maximum vertical displacements and horizontal support reaction of the cable truss on the intensity of vertical load in cases of symmetric and unsymmetrical loading were obtained for both physical models. Possibility to decrease the cable truss materials consumption by 17% by taking into account combined work of prestressed cable trusses and cross-laminated timber panels was stated.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"234-240"},"PeriodicalIF":1.1,"publicationDate":"2017-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48370534","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}
Modelling of the pavement temperature facilitates winter road maintenance. It is used for predicting the glaze formation and for scheduling the spraying of the de-icing brine. The road weather is commonly forecasted by solving the energy balance equations. It requires setting the initial vertical profile of the pavement temperature, which is often obtained from the Road Weather Information Stations. The paper proposes the use of average air temperature from seven preceding days as a pseudo-observation of the subsurface temperature. Next, the road weather model is run with a few days offset. It first uses the recent, historical weather data and then the available forecasts. This approach exploits the fact that the energy balance models tend to “forget” their initial conditions and converge to the baseline solution. The experimental verification was conducted using the Model of the Environment and Temperature of Roads and the data from a road weather station in Warsaw over a period of two years. The additional forecast error introduced by the proposed pseudo-observational initialization averages 1.2 °C in the first prediction hour and then decreases in time. The paper also discusses the use of Digital Surface Models to take into account the shading effects, which are an essential source of forecast errors in urban areas. Limiting the use of in-situ sensors opens a perspective for an economical, large-scale implementation of road meteorological models.
{"title":"Road Temperature Modelling Without In-Situ Sensors","authors":"K. Opara, J. Zielinski","doi":"10.3846/BJRBE.2017.30","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.30","url":null,"abstract":"Modelling of the pavement temperature facilitates winter road maintenance. It is used for predicting the glaze formation and for scheduling the spraying of the de-icing brine. The road weather is commonly forecasted by solving the energy balance equations. It requires setting the initial vertical profile of the pavement temperature, which is often obtained from the Road Weather Information Stations. The paper proposes the use of average air temperature from seven preceding days as a pseudo-observation of the subsurface temperature. Next, the road weather model is run with a few days offset. It first uses the recent, historical weather data and then the available forecasts. This approach exploits the fact that the energy balance models tend to “forget” their initial conditions and converge to the baseline solution. The experimental verification was conducted using the Model of the Environment and Temperature of Roads and the data from a road weather station in Warsaw over a period of two years. The additional forecast error introduced by the proposed pseudo-observational initialization averages 1.2 °C in the first prediction hour and then decreases in time. The paper also discusses the use of Digital Surface Models to take into account the shading effects, which are an essential source of forecast errors in urban areas. Limiting the use of in-situ sensors opens a perspective for an economical, large-scale implementation of road meteorological models.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"241-247"},"PeriodicalIF":1.1,"publicationDate":"2017-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47306863","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 recent reconstruction of the historical masonry Charles Bridge in Prague was designed with respect to original conception, materials and ancient construction techniques. The repair and remedial works were based on analysis of the multi-decade response of the bridge, diagnosis, and assessment of damages, failures and deterioration processes related to materials, environment, climate, structural arrangement and detailing regarding heritage, historical and structural aspects. The gentle way of remedial works with minimal intervention in the loadbearing structure is a result of a wide-range discussion on appropriate strategies for refurbishment, restoration, conservation and preservation corresponding to location and significance of the historic bridge. The reconstruction increased durability and provides a long service life of the historical bridge and protection against harmful effects for many years to come. The article outlines historical data, consequences of the controversial reconstruction in the second half of the last century. Effects of river flow, temperature, and moisture and their influence on needful repairs are considered. Stages of reconstruction are presented; in the first stage, strengthening of foundations of bridge piers is described including historical background and impact of river flow on subgrade of piers. Ways of repairs and reconstruction of the bridge deck, its draining, and other related bridge elements are shown as a part of the second stage of reconstruction.
{"title":"Remedial Works and Repairs of Historical Bridge in Prague","authors":"I. Broukalová, V. Krístek","doi":"10.3846/BJRBE.2017.33","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.33","url":null,"abstract":"The recent reconstruction of the historical masonry Charles Bridge in Prague was designed with respect to original conception, materials and ancient construction techniques. The repair and remedial works were based on analysis of the multi-decade response of the bridge, diagnosis, and assessment of damages, failures and deterioration processes related to materials, environment, climate, structural arrangement and detailing regarding heritage, historical and structural aspects. The gentle way of remedial works with minimal intervention in the loadbearing structure is a result of a wide-range discussion on appropriate strategies for refurbishment, restoration, conservation and preservation corresponding to location and significance of the historic bridge. The reconstruction increased durability and provides a long service life of the historical bridge and protection against harmful effects for many years to come. The article outlines historical data, consequences of the controversial reconstruction in the second half of the last century. Effects of river flow, temperature, and moisture and their influence on needful repairs are considered. Stages of reconstruction are presented; in the first stage, strengthening of foundations of bridge piers is described including historical background and impact of river flow on subgrade of piers. Ways of repairs and reconstruction of the bridge deck, its draining, and other related bridge elements are shown as a part of the second stage of reconstruction.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"264-269"},"PeriodicalIF":1.1,"publicationDate":"2017-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41992947","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 research aims to assess the relationships between the crash rates and road consistency. Design consistency assessment is a tool employed by designers to improve road safety. The case study involved a rural two-lane two-way road in Southern Italy located on a flat terrain without spiral transition curves between tangent segments and circular curves. Road alignment consistency was examined in two steps: by adopting standards in force in Italy based on the design speed profile and by plotting operating speed profile to determine the area bounded by the speed profile and the average weighted speed, and the standard deviation of operating speeds for each geometric segment. Operating speed prediction model, which returns the 85th percentile of the speed distribution of the only cars under free flow conditions, right weather conditions, and lighting was adopted. A negative exponential function was performed to predict the global consistency of a road as a whole. Finally, a model for predicting the crash rate was calibrated, confirming an increase of design consistency when the crash rates decrease significantly. The consistency model represents a useful tool during the geometric design process or the evaluation process for two-lane rural highways.
{"title":"Countermeasures to Improve Road Alignment Consistency of Undivided Rural Roads","authors":"F. Russo, S. A. Biancardo","doi":"10.3846/BJRBE.2017.26","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.26","url":null,"abstract":"The research aims to assess the relationships between the crash rates and road consistency. Design consistency assessment is a tool employed by designers to improve road safety. The case study involved a rural two-lane two-way road in Southern Italy located on a flat terrain without spiral transition curves between tangent segments and circular curves. Road alignment consistency was examined in two steps: by adopting standards in force in Italy based on the design speed profile and by plotting operating speed profile to determine the area bounded by the speed profile and the average weighted speed, and the standard deviation of operating speeds for each geometric segment. Operating speed prediction model, which returns the 85th percentile of the speed distribution of the only cars under free flow conditions, right weather conditions, and lighting was adopted. A negative exponential function was performed to predict the global consistency of a road as a whole. Finally, a model for predicting the crash rate was calibrated, confirming an increase of design consistency when the crash rates decrease significantly. The consistency model represents a useful tool during the geometric design process or the evaluation process for two-lane rural highways.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"211-217"},"PeriodicalIF":1.1,"publicationDate":"2017-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45377927","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 aim of this paper is to investigate the time-varying effect of stay cable of long-span cable-stayed bridges subject to vehicle load. The analysis has been carried out on the Su-Tong cable-stayed bridge in Jiangsu, China that has the second-longest span among the completed composite-deck cable-stayed bridges in the world currently. Probability models of vehicle load in each lane (fast lane, middle lane and slow lane) and cable stress under random vehicle load were developed based on the stochastic process theory. The results show the gross vehicle weight follows lognormal distribution or multi-peak distribution, and the time-interval of the vehicle follows a lognormal distribution. Then, the probability function of maximum cable stress was determined using up-crossing theory. Finally, the reliability of stay cable under random vehicle load was analysed. The reliability index ranges from 9.59 to 10.82 that satisfies the target reliability index of highway bridge structure of finished dead state.
{"title":"Probability Model and Reliability Analysis of Cable Stress for Cable-Stayed Bridge","authors":"Xiao-Yan Yang, Jinxin Gong, Yin-hui Wang, Bo-Han Xu, Jichao Zhu","doi":"10.3846/BJRBE.2017.31","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.31","url":null,"abstract":"The aim of this paper is to investigate the time-varying effect of stay cable of long-span cable-stayed bridges subject to vehicle load. The analysis has been carried out on the Su-Tong cable-stayed bridge in Jiangsu, China that has the second-longest span among the completed composite-deck cable-stayed bridges in the world currently. Probability models of vehicle load in each lane (fast lane, middle lane and slow lane) and cable stress under random vehicle load were developed based on the stochastic process theory. The results show the gross vehicle weight follows lognormal distribution or multi-peak distribution, and the time-interval of the vehicle follows a lognormal distribution. Then, the probability function of maximum cable stress was determined using up-crossing theory. Finally, the reliability of stay cable under random vehicle load was analysed. The reliability index ranges from 9.59 to 10.82 that satisfies the target reliability index of highway bridge structure of finished dead state.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"248-257"},"PeriodicalIF":1.1,"publicationDate":"2017-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43332096","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}
This paper introduces a possible way to use a multivariate methodology, called principal component analysis, to reduce the dimensionality of condition state database of bridge elements, collected during visual inspections. Attention is paid to the condition assessment of bridges in Estonian national roads and collected data, which plays an important role in the selection of correct statistical technique and obtaining reliable results. Additionally, detailed overview of typical road bridges and examples of collected information is provided. Statistical analysis is carried out by most natural reinforced concrete bridges in Estonia and comparison is made among different typologies. The introduced multivariate technique algorithms are presented and collated in two different formulations, with contrast on unevenness in variables and taking into account the missing data. Principal components and weighing factors, which are calculated for bridges with different typology, also have differences in results and element groups where variation is retained.
{"title":"Statistical analysis of reinforced concrete bridges in Estonia","authors":"S. Sein, J. Matos, J. Idnurm","doi":"10.3846/BJRBE.2017.28","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.28","url":null,"abstract":"This paper introduces a possible way to use a multivariate methodology, called principal component analysis, to reduce the dimensionality of condition state database of bridge elements, collected during visual inspections. Attention is paid to the condition assessment of bridges in Estonian national roads and collected data, which plays an important role in the selection of correct statistical technique and obtaining reliable results. Additionally, detailed overview of typical road bridges and examples of collected information is provided. Statistical analysis is carried out by most natural reinforced concrete bridges in Estonia and comparison is made among different typologies. The introduced multivariate technique algorithms are presented and collated in two different formulations, with contrast on unevenness in variables and taking into account the missing data. Principal components and weighing factors, which are calculated for bridges with different typology, also have differences in results and element groups where variation is retained.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"225-233"},"PeriodicalIF":1.1,"publicationDate":"2017-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46279829","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}
Zhongyu Li, Tingguo Liu, Jicun Shi, U. Veranko, V. Zankavich
This article presents the results of research of processes of deformation and destruction of asphalt concrete pavements under cyclic loads. As the ground for such approach to estimation of the asphalt concrete properties served the proof that regardless of the composition and structure of asphalt concrete with an equal amount of elastic (viscoplastic) bonds possess the same relaxation ability. This situation is a significant feature of the behaviour of asphalt concrete, which opens the way for the development of certain approaches to the analysis of their properties, evaluation of reliability and durability. The promising methodology for the comparative assessment of fatigue and cyclic durability of asphalt concrete by exploring the complex set of elastic and viscoplastic bonds in their structure depending on the temperature, magnitude, and modes of action of the loads is proposed in the presented work. In the future, the establishment of patterns of behaviour of asphalt concretes with the same set of elastic bonds is allows to optimize compositions based on the principles of temperature-structural analogy that is relevant in studying fatigue and cyclic durability as well as low-temperature crack resistance and shear stability.
{"title":"Fatigue Resistance of Asphalt Concrete Pavements. Peculiarity and Assessments of Potentials","authors":"Zhongyu Li, Tingguo Liu, Jicun Shi, U. Veranko, V. Zankavich","doi":"10.3846/BJRBE.2017.34","DOIUrl":"https://doi.org/10.3846/BJRBE.2017.34","url":null,"abstract":"This article presents the results of research of processes of deformation and destruction of asphalt concrete pavements under cyclic loads. As the ground for such approach to estimation of the asphalt concrete properties served the proof that regardless of the composition and structure of asphalt concrete with an equal amount of elastic (viscoplastic) bonds possess the same relaxation ability. This situation is a significant feature of the behaviour of asphalt concrete, which opens the way for the development of certain approaches to the analysis of their properties, evaluation of reliability and durability. The promising methodology for the comparative assessment of fatigue and cyclic durability of asphalt concrete by exploring the complex set of elastic and viscoplastic bonds in their structure depending on the temperature, magnitude, and modes of action of the loads is proposed in the presented work. In the future, the establishment of patterns of behaviour of asphalt concretes with the same set of elastic bonds is allows to optimize compositions based on the principles of temperature-structural analogy that is relevant in studying fatigue and cyclic durability as well as low-temperature crack resistance and shear stability.","PeriodicalId":55402,"journal":{"name":"Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"270-275"},"PeriodicalIF":1.1,"publicationDate":"2017-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46214340","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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