Haonan Zhou, Haifeng Zhang, Zhoucong Xu, Tianlong Chen, H. Wang
In this study, we used the SEM electron microscope to observe the morphological characteristics of each phase interface in the mixture, focusing on the effects of gradation, cement content, curing age, and mixing method on the unconfined compressive strength and splitting strength of the cold recycled mixture, to optimize the material composition design of cement composite recycled mixture. The results showed that dry shrinkage cracks and cement aggregates appeared on the surface of the three aggregates formed by conventional mixing, while the old cement that was not closely connected on the RBP surface of the mixture fell off using the vibration mixing method. The cement on the surface of all kinds of aggregates was evenly coated, with a reduced interface strength variability. The strength of the mixture increased with age was in line with the law of cement strength growth; The increase in cement content could increase the unconfined compressive strength and splitting strength of the mixture; The strength of the mixture increased and then decreased with the increase of RAP content. The unconfined compressive strength and splitting strength of the mixture were increased by 32.4% and 44.3%, and the coefficient of variation was reduced by 27.1% and 31.0%, respectively, by using vibration mixing compared with conventional mixing.
{"title":"Factors affecting the strength of cement composite cold recycled mixture and its interface morphological characteristics","authors":"Haonan Zhou, Haifeng Zhang, Zhoucong Xu, Tianlong Chen, H. Wang","doi":"10.1117/12.2658576","DOIUrl":"https://doi.org/10.1117/12.2658576","url":null,"abstract":"In this study, we used the SEM electron microscope to observe the morphological characteristics of each phase interface in the mixture, focusing on the effects of gradation, cement content, curing age, and mixing method on the unconfined compressive strength and splitting strength of the cold recycled mixture, to optimize the material composition design of cement composite recycled mixture. The results showed that dry shrinkage cracks and cement aggregates appeared on the surface of the three aggregates formed by conventional mixing, while the old cement that was not closely connected on the RBP surface of the mixture fell off using the vibration mixing method. The cement on the surface of all kinds of aggregates was evenly coated, with a reduced interface strength variability. The strength of the mixture increased with age was in line with the law of cement strength growth; The increase in cement content could increase the unconfined compressive strength and splitting strength of the mixture; The strength of the mixture increased and then decreased with the increase of RAP content. The unconfined compressive strength and splitting strength of the mixture were increased by 32.4% and 44.3%, and the coefficient of variation was reduced by 27.1% and 31.0%, respectively, by using vibration mixing compared with conventional mixing.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124002570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The braking work of the retarder directly determines its braking effect on the skidding wagon. The larger the braking work, the better the braking effect. Based on a new magnetorheological retarder, this paper analyzes the braking process of the new magnetorheological retarder and gives the calculation of the braking work of this retarder. The result shows that the magnetorheological retarder can output appropriate braking work, and the physical and mechanical properties of the magnetorheological material have a large influence on the braking work of this type of retarder.
{"title":"Analysis of braking work of speed-control magnetorheological retarder of wagon at marshaling station","authors":"Runpu Li, Shuang-Ji Wang, Tianxing Pu, Jiang-le Zhu","doi":"10.1117/12.2658693","DOIUrl":"https://doi.org/10.1117/12.2658693","url":null,"abstract":"The braking work of the retarder directly determines its braking effect on the skidding wagon. The larger the braking work, the better the braking effect. Based on a new magnetorheological retarder, this paper analyzes the braking process of the new magnetorheological retarder and gives the calculation of the braking work of this retarder. The result shows that the magnetorheological retarder can output appropriate braking work, and the physical and mechanical properties of the magnetorheological material have a large influence on the braking work of this type of retarder.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129018371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Steel bridges have the advantages of light weight, high strength, prefabricated construction, and short construction time, and therefore have been widely used in many countries. In conventional bridge design, the load bearing capacity of the structure is considered as the most important safety factor. However, as the service life increases, the actual load-carrying capacity of bridges gradually decreases due to the combined action of the environmental corrosion and repeated vehicle loads, resulting in shortened bridge service life. In this paper, the fatigue reliability index of a steel girder bridge over its whole life is investigated based on artificial neural networks. The effects of truck traffic load and environmental corrosivity on the fatigue life of the steel girder bridge are analyzed and measures to control the traffic load are discussed. The research results can serve as a reference for traffic load management of highway steel bridges.
{"title":"Fatigue reliability analysis and traffic load control of steel bridges based on artificial neural network","authors":"Lei Nie, Wei Wang, L. Deng","doi":"10.1117/12.2658303","DOIUrl":"https://doi.org/10.1117/12.2658303","url":null,"abstract":"Steel bridges have the advantages of light weight, high strength, prefabricated construction, and short construction time, and therefore have been widely used in many countries. In conventional bridge design, the load bearing capacity of the structure is considered as the most important safety factor. However, as the service life increases, the actual load-carrying capacity of bridges gradually decreases due to the combined action of the environmental corrosion and repeated vehicle loads, resulting in shortened bridge service life. In this paper, the fatigue reliability index of a steel girder bridge over its whole life is investigated based on artificial neural networks. The effects of truck traffic load and environmental corrosivity on the fatigue life of the steel girder bridge are analyzed and measures to control the traffic load are discussed. The research results can serve as a reference for traffic load management of highway steel bridges.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"12460 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130118357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Based on the fire numerical simulation, the movement characteristics of fire smoke in the super large space above the ground interchange is studied. In view of the characteristics of the overpass tunnel with large span, large space, many diversion and confluence nodes, the smoke layer morphological characteristics and smoke temperature distribution of different longitudinal air velocity under the longitudinal smoke exhaust mode are studied, and the critical air velocity of smoke flow, smoke diffusion characteristics and smoke control technology in the overpass tunnel are analyzed. The results show that after the partition between the lanes in the same direction is removed, due to the expansion of the section, the wind velocity in the original branch ramp can not effectively suppress the smoke countercurrent, and the critical smoke exhaust air velocity will increase; After canceling the same direction partition between ramps, under all calculation conditions, except for the fire source area, the other indicators 1.8 m above the ground meet the needs of personnel evacuation and escape, and the longitudinal smoke exhaust air velocity that controls the smoke not to produce countercurrent is 3.0 m/s.
{"title":"Study on smoke transport characteristics in super large space of covered ground interchange","authors":"Chun-Ho Liu, Zhengmao Cao","doi":"10.1117/12.2658629","DOIUrl":"https://doi.org/10.1117/12.2658629","url":null,"abstract":"Based on the fire numerical simulation, the movement characteristics of fire smoke in the super large space above the ground interchange is studied. In view of the characteristics of the overpass tunnel with large span, large space, many diversion and confluence nodes, the smoke layer morphological characteristics and smoke temperature distribution of different longitudinal air velocity under the longitudinal smoke exhaust mode are studied, and the critical air velocity of smoke flow, smoke diffusion characteristics and smoke control technology in the overpass tunnel are analyzed. The results show that after the partition between the lanes in the same direction is removed, due to the expansion of the section, the wind velocity in the original branch ramp can not effectively suppress the smoke countercurrent, and the critical smoke exhaust air velocity will increase; After canceling the same direction partition between ramps, under all calculation conditions, except for the fire source area, the other indicators 1.8 m above the ground meet the needs of personnel evacuation and escape, and the longitudinal smoke exhaust air velocity that controls the smoke not to produce countercurrent is 3.0 m/s.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130149665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flex-route feeder transit is a promising way to improve the flexibility of first/last mile service. In this paper, we propose an optimal scheduling strategy which can provide immediate feedback to enhance the attraction of flex-route feeder transit. An improved cycle length model and a modified scheduling algorithm are proposed to guarantee the performance and the reliability of feeder system. Six indicators are employed to evaluate the performance of flex-route feeder transit from macroscopic and microcosmic aspects. Finally, simulation experiments with different system parameter values are conducted using the proposed model and algorithm. The results verify the validity of the optimal method and indicate that our optimal design for flex-route feeder transit can help the decision-makers best select from the transit modes in different situations.
{"title":"Discussion about cycle length, scheduling algorithm, and headways for flex-route feeder transit","authors":"Zike Shao, Chunyang Sun, Ya Liu","doi":"10.1117/12.2657954","DOIUrl":"https://doi.org/10.1117/12.2657954","url":null,"abstract":"Flex-route feeder transit is a promising way to improve the flexibility of first/last mile service. In this paper, we propose an optimal scheduling strategy which can provide immediate feedback to enhance the attraction of flex-route feeder transit. An improved cycle length model and a modified scheduling algorithm are proposed to guarantee the performance and the reliability of feeder system. Six indicators are employed to evaluate the performance of flex-route feeder transit from macroscopic and microcosmic aspects. Finally, simulation experiments with different system parameter values are conducted using the proposed model and algorithm. The results verify the validity of the optimal method and indicate that our optimal design for flex-route feeder transit can help the decision-makers best select from the transit modes in different situations.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"12460 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129187738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the excessive travel volume in urban rail transit operations and the mismatch between supply and demand, it is necessary to restrict the passenger flow of some stations, so that the passenger flow can match the station capacity. Therefore, based on the barrel principle, this study takes the station as the key observation point, divides the service level into different levels, and judges whether the passenger flow control measures are triggered. Finally, we use the simulation software MassMotion to build the Longze Station model for case study. The results show that the adoption of passenger flow control measures has a significant impact on improving the service level of the station, effectively reducing the number of people gathered on the platform and the passenger flow density in the bottleneck area.
{"title":"Traffic restriction organization of urban rail transit station","authors":"Fan Xu, Xiao Liang","doi":"10.1117/12.2657823","DOIUrl":"https://doi.org/10.1117/12.2657823","url":null,"abstract":"Due to the excessive travel volume in urban rail transit operations and the mismatch between supply and demand, it is necessary to restrict the passenger flow of some stations, so that the passenger flow can match the station capacity. Therefore, based on the barrel principle, this study takes the station as the key observation point, divides the service level into different levels, and judges whether the passenger flow control measures are triggered. Finally, we use the simulation software MassMotion to build the Longze Station model for case study. The results show that the adoption of passenger flow control measures has a significant impact on improving the service level of the station, effectively reducing the number of people gathered on the platform and the passenger flow density in the bottleneck area.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124722425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heterogeneous collaborative systems consisting of unmanned aerial vehicles/ground vehicles (UAV/UGV) have great potential for application in many fields. Among other things, UAV can provide a wide field of view and photography, while UGV can provide sufficient load capacity and act as relay stations. Rational planning of UAV/UGV paths based on actual tasks is an important issue to be addressed. This study proposes a hybrid unmanned system based on coordinated cooperation between UAV /UGV. In this system, the UGV is used as a mobile charging station to solve the UAV energy constraint problem. The UAV is used as a robotic system responsible for reaching the target point and solving the UGV functional constraint problem. We propose a path planning method for the study of two robots working together. A hierarchical path optimization strategy that combines classical and modern evolutionary methods. The method takes full advantage of the strengths of individual methods and algorithms in path selection and planning. Simulation results show that the collaborative UAV and UGV systems can improve the efficiency of performing tasks and that the hierarchical optimization strategy can improve the solution quality and stability of path planning.
{"title":"A hierarchical optimal path planning algorithm for collaborative air-ground inspection","authors":"Yuanguang Zhang, Yuhong Zhao, Ziqi Zhao, Weiqi Tang","doi":"10.1117/12.2658244","DOIUrl":"https://doi.org/10.1117/12.2658244","url":null,"abstract":"Heterogeneous collaborative systems consisting of unmanned aerial vehicles/ground vehicles (UAV/UGV) have great potential for application in many fields. Among other things, UAV can provide a wide field of view and photography, while UGV can provide sufficient load capacity and act as relay stations. Rational planning of UAV/UGV paths based on actual tasks is an important issue to be addressed. This study proposes a hybrid unmanned system based on coordinated cooperation between UAV /UGV. In this system, the UGV is used as a mobile charging station to solve the UAV energy constraint problem. The UAV is used as a robotic system responsible for reaching the target point and solving the UGV functional constraint problem. We propose a path planning method for the study of two robots working together. A hierarchical path optimization strategy that combines classical and modern evolutionary methods. The method takes full advantage of the strengths of individual methods and algorithms in path selection and planning. Simulation results show that the collaborative UAV and UGV systems can improve the efficiency of performing tasks and that the hierarchical optimization strategy can improve the solution quality and stability of path planning.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116427527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Jiang, Guifeng Chen, Jie Mei, Fei Zhang, Guangqiang Huang, Guokai Gao, Kang Chen
The anti-skid performance of asphalt pavement is the key index to judge the safety of pavement, and excellent anti-skid performance is also the most effective means to ensure the safety of vehicles. In many years of road operation and management, it is found that the loss of skid resistance of asphalt pavement is the most common disease in the road. Due to the decrease of road skid resistance, traffic safety and road service quality are seriously affected. In view of the factors affecting the skid resistance of asphalt pavement, the tire factors, materials, grading types, construction technology, operation and maintenance management are summarized. This paper analyzes the reasons for the attenuation of anti-skid performance of asphalt pavement by vehicle load, running time, water and pollutants, and the relevant test methods and evaluation models of anti-skid performance of asphalt pavement.
{"title":"Analysis of influencing factors, test method and evaluation model on skid resistance of asphalt pavement","authors":"J. Jiang, Guifeng Chen, Jie Mei, Fei Zhang, Guangqiang Huang, Guokai Gao, Kang Chen","doi":"10.1117/12.2658157","DOIUrl":"https://doi.org/10.1117/12.2658157","url":null,"abstract":"The anti-skid performance of asphalt pavement is the key index to judge the safety of pavement, and excellent anti-skid performance is also the most effective means to ensure the safety of vehicles. In many years of road operation and management, it is found that the loss of skid resistance of asphalt pavement is the most common disease in the road. Due to the decrease of road skid resistance, traffic safety and road service quality are seriously affected. In view of the factors affecting the skid resistance of asphalt pavement, the tire factors, materials, grading types, construction technology, operation and maintenance management are summarized. This paper analyzes the reasons for the attenuation of anti-skid performance of asphalt pavement by vehicle load, running time, water and pollutants, and the relevant test methods and evaluation models of anti-skid performance of asphalt pavement.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127392690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the complex topography and geological conditions of the mountainous two-lane highway, the road alignment is complex, the excavation is more, the road space is complex and changeable, and traffic safety accidents are frequent. In order to explore the influencing factors that affect the driver's visual load, this paper systematically sorts out the research on the driver's visual load in the field of road traffic safety, and summarizes the concept, influencing factors and evaluation methods of visual load. In future research, it is necessary to consider the influencing factors and changing laws from more angles, and conduct a comprehensive study.
{"title":"Research on evolution of visual load of mountain highway driving","authors":"Y. Meng, Shibao Li, G. Qing, Wei-yong Gong","doi":"10.1117/12.2658151","DOIUrl":"https://doi.org/10.1117/12.2658151","url":null,"abstract":"Due to the complex topography and geological conditions of the mountainous two-lane highway, the road alignment is complex, the excavation is more, the road space is complex and changeable, and traffic safety accidents are frequent. In order to explore the influencing factors that affect the driver's visual load, this paper systematically sorts out the research on the driver's visual load in the field of road traffic safety, and summarizes the concept, influencing factors and evaluation methods of visual load. In future research, it is necessary to consider the influencing factors and changing laws from more angles, and conduct a comprehensive study.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128427264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aiming at the difficulty of accurately segmenting pavement cracks in traditional detection methods, this paper proposes a lightweight real-time detection model named MFPNet with an end-to-end encoding and decoding structure. Firstly, in the encoding stage, based on the different extraction characteristics of the involution-G and convolution operators for cracks, the designed multi-type features parallel (MFP) module is used in the deep network to enhance the abstract semantic information with reducing information loss. Then, the simplified long connection structure is adopted in the decoding stage to maintain the detection speed without reducing the detection accuracy. Additionally, ablation experiments demonstrate the effectiveness of the designed module. What’s more, compared with other deep learning-based algorithms, the model proposed in this paper has excellent performance, and its MIOU, Recall, and F1 Score reach 0.7705, 0.8023, and 0.8485, respectively. In practice, MFPNet can be implemented in images with a high resolution of 2048×1024 in real time.
{"title":"MFPNet: using multi-type features parallelism in deep layers to improve segmentation performance for pavement cracks","authors":"Pengfei Yong","doi":"10.1117/12.2658623","DOIUrl":"https://doi.org/10.1117/12.2658623","url":null,"abstract":"Aiming at the difficulty of accurately segmenting pavement cracks in traditional detection methods, this paper proposes a lightweight real-time detection model named MFPNet with an end-to-end encoding and decoding structure. Firstly, in the encoding stage, based on the different extraction characteristics of the involution-G and convolution operators for cracks, the designed multi-type features parallel (MFP) module is used in the deep network to enhance the abstract semantic information with reducing information loss. Then, the simplified long connection structure is adopted in the decoding stage to maintain the detection speed without reducing the detection accuracy. Additionally, ablation experiments demonstrate the effectiveness of the designed module. What’s more, compared with other deep learning-based algorithms, the model proposed in this paper has excellent performance, and its MIOU, Recall, and F1 Score reach 0.7705, 0.8023, and 0.8485, respectively. In practice, MFPNet can be implemented in images with a high resolution of 2048×1024 in real time.","PeriodicalId":212840,"journal":{"name":"Conference on Smart Transportation and City Engineering","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127042701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：