The Experts below are selected from a list of 2106 Experts worldwide ranked by ideXlab platform
Jing Guoqing - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical study on lateral resistance of frictional sleeper with arrowhead groove
'Elsevier BV', 2021Co-Authors: Jing Guoqing, Markine V.l., Jia W., Wang Xinyu, Nålsund Roar, Guo Y.Abstract:To enhance the stability of continuous welded rail (CWR) Tracks, frictional sleepers have been developed. The frictional sleepers are new types of sleepers with grooves on the bottom, and different bottom grooves improve lateral resistances at different magnitudes. In this study, single sleeper push test (SSPT) and its model with discrete element method (DEM) were carried out to confirm how much arrowhead groove frictional (AGF) sleeper increases the lateral resistance of Ballasted Track. The SSPTs were performed to confirm the lateral resistance results, and also to validate and calibrate the DEM models. With the validated models, the groove factors influencing the lateral resistances were studied, including groove sizes (depth, width), arrowhead groove direction and groove numbers. The reason of lateral resistance improvement was studied at mesoscopic level, including the ballast-sleeper contact numbers and contact force chains. Results show that applying the AGF sleeper is able to improve lateral resistance by 7–24%, and it can provide enough lateral resistance after reducing ballast shoulder width from 500 mm to 300 mm. The AGF sleeper can improve the sleeper-ballast interaction by increasing sleeper-ballast contact number. The study is helpful for frictional sleeper design, further improving Track stability.Railway Engineerin
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Effect of sleeper bottom texture on lateral resistance with discrete element modelling
'Elsevier BV', 2020Co-Authors: Guo Y., Markine V.l., Fu Hao, Yu Qian, Jing GuoqingAbstract:The lateral stability of Ballasted Track becomes more important because of the safety requirement under the demand of higher train speed and heavier axle load. To increase the lateral resistance of ballast bed, this paper proposes three types of new sleepers, frictional sleepers. The frictional sleepers are sleepers with different shapes of textures attached at the sleeper bottom. To study the application feasibility of the frictional sleepers, experimental tests (single sleeper pull-out test) and numerical simulation (discrete element modelling) are performed. The lateral resistances of the three types of frictional sleepers are compared with the traditional sleeper based on the experimental test, and the mechanism of the lateral resistance increase is revealed according to the numerical simulation. The results indicate that the frictional sleepers can increase the lateral resistance by 32% (maximum), due to the enhanced interaction between sleeper and ballast particles. More importantly, different types of frictional sleepers have different performances, and the optimal friction sleeper is confirmed. This study is helpful for the further research on sleeper design.
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Effect of sleeper bottom texture on lateral resistance with discrete element modelling
'Elsevier BV', 2020Co-Authors: Guo Y., Markine V.l., Fu Hao, Yu Qian, Jing GuoqingAbstract:The lateral stability of Ballasted Track becomes more important because of the safety requirement under the demand of higher train speed and heavier axle load. To increase the lateral resistance of ballast bed, this paper proposes three types of new sleepers, frictional sleepers. The frictional sleepers are sleepers with different shapes of textures attached at the sleeper bottom. To study the application feasibility of the frictional sleepers, experimental tests (single sleeper pull-out test) and numerical simulation (discrete element modelling) are performed. The lateral resistances of the three types of frictional sleepers are compared with the traditional sleeper based on the experimental test, and the mechanism of the lateral resistance increase is revealed according to the numerical simulation. The results indicate that the frictional sleepers can increase the lateral resistance by 32% (maximum), due to the enhanced interaction between sleeper and ballast particles. More importantly, different types of frictional sleepers have different performances, and the optimal friction sleeper is confirmed. This study is helpful for the further research on sleeper design.Accepted Author ManuscriptRailway Engineerin
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Polyurethane reinforced Ballasted Track: Review, innovation and challenge
'Elsevier BV', 2019Co-Authors: Jing Guoqing, Markine V.l., Qie Luchao, Jia W.Abstract:During the development for railway, Ballasted Track is dominant structure and makes up more than 95% of the whole Track modes. However, its shortage is considerable in high speed railway and heavy haul system. Regarding to the Ballasted railway Track's defects as particle breakage, settlement, and geometry irregularity which lead to enormous maintenance and cost. Polyurethane reinforced Ballasted Track has shown great application prospect. This reinforcement method can settle several problems, including stiffness adjustment, ballast flight prevention, and stability in specific zones, such as curve, tunnel line. This paper presents a comprehensive review of polyurethane research and application within Ballasted Track system. Besides, according to different usage, varies of bonding methods are also introduced in this paper. However, some challenges still exist such as maintenance and cost, potential solutions are put forward for further investigated and validated, consequently. Accordingly, an overall prospect of polyurethane reinforcement in railway system is presented
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Polyurethane reinforced Ballasted Track: Review, innovation and challenge
'Elsevier BV', 2019Co-Authors: Jing Guoqing, Markine V.l., Qie Luchao, Jia W.Abstract:During the development for railway, Ballasted Track is dominant structure and makes up more than 95% of the whole Track modes. However, its shortage is considerable in high speed railway and heavy haul system. Regarding to the Ballasted railway Track's defects as particle breakage, settlement, and geometry irregularity which lead to enormous maintenance and cost. Polyurethane reinforced Ballasted Track has shown great application prospect. This reinforcement method can settle several problems, including stiffness adjustment, ballast flight prevention, and stability in specific zones, such as curve, tunnel line. This paper presents a comprehensive review of polyurethane research and application within Ballasted Track system. Besides, according to different usage, varies of bonding methods are also introduced in this paper. However, some challenges still exist such as maintenance and cost, potential solutions are put forward for further investigated and validated, consequently. Accordingly, an overall prospect of polyurethane reinforcement in railway system is presented.Accepted Author ManuscriptRailway Engineerin
Guoqing Jing - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical study on lateral resistance of frictional sleeper with arrowhead groove
Transportation geotechnics, 2021Co-Authors: Guoqing Jing, Wenli Jia, Xinyu Wang, V L Markine, Roar Nalsund, Yunlong GuoAbstract:Abstract To enhance the stability of continuous welded rail (CWR) Tracks, frictional sleepers have been developed. The frictional sleepers are new types of sleepers with grooves on the bottom, and different bottom grooves improve lateral resistances at different magnitudes. In this study, single sleeper push test (SSPT) and its model with discrete element method (DEM) were carried out to confirm how much arrowhead groove frictional (AGF) sleeper increases the lateral resistance of Ballasted Track. The SSPTs were performed to confirm the lateral resistance results, and also to validate and calibrate the DEM models. With the validated models, the groove factors influencing the lateral resistances were studied, including groove sizes (depth, width), arrowhead groove direction and groove numbers. The reason of lateral resistance improvement was studied at mesoscopic level, including the ballast-sleeper contact numbers and contact force chains. Results show that applying the AGF sleeper is able to improve lateral resistance by 7–24%, and it can provide enough lateral resistance after reducing ballast shoulder width from 500 mm to 300 mm. The AGF sleeper can improve the sleeper-ballast interaction by increasing sleeper-ballast contact number. The study is helpful for frictional sleeper design, further improving Track stability.
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the contribution of ballast layer components to the lateral resistance of ladder sleeper Track
Construction and Building Materials, 2019Co-Authors: Guoqing Jing, Peyman Aela, Hao FuAbstract:Abstract The sleeper-ballast interface of railway Tracks directly is associated with lateral resistance which plays an important role in the mechanical behavior of Ballasted Tracks. In a real-case implementation of Ballasted Track for speeds as high as 400 km/h, sufficient lateral resistance is vital to prevent the lateral movement of the Track. In view of the future development, a series of full-scale lateral Track panel tests (LTPT) were conducted to evaluate the lateral resistance of ladder sleepers as a substitution of monoblock sleepers. The experimental results revealed that the application of the ladder sleepers caused an increase in lateral resistance of the Ballasted Track as well as a reduction in the use of ballast aggregates. In addition, the contribution of the ladder sleeper facets to the lateral resistance was investigated by the discrete element method (DEM). In conclusion, crib ballast has the main role in the lateral resistance of ladder sleeper Tracks.
Guo Y. - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical study on lateral resistance of frictional sleeper with arrowhead groove
'Elsevier BV', 2021Co-Authors: Jing Guoqing, Markine V.l., Jia W., Wang Xinyu, Nålsund Roar, Guo Y.Abstract:To enhance the stability of continuous welded rail (CWR) Tracks, frictional sleepers have been developed. The frictional sleepers are new types of sleepers with grooves on the bottom, and different bottom grooves improve lateral resistances at different magnitudes. In this study, single sleeper push test (SSPT) and its model with discrete element method (DEM) were carried out to confirm how much arrowhead groove frictional (AGF) sleeper increases the lateral resistance of Ballasted Track. The SSPTs were performed to confirm the lateral resistance results, and also to validate and calibrate the DEM models. With the validated models, the groove factors influencing the lateral resistances were studied, including groove sizes (depth, width), arrowhead groove direction and groove numbers. The reason of lateral resistance improvement was studied at mesoscopic level, including the ballast-sleeper contact numbers and contact force chains. Results show that applying the AGF sleeper is able to improve lateral resistance by 7–24%, and it can provide enough lateral resistance after reducing ballast shoulder width from 500 mm to 300 mm. The AGF sleeper can improve the sleeper-ballast interaction by increasing sleeper-ballast contact number. The study is helpful for frictional sleeper design, further improving Track stability.Railway Engineerin
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Analysis of Railway Ballasted Track Stiffness and Behavior with a Hybrid Discrete-Continuum Approach
'American Society of Civil Engineers (ASCE)', 2021Co-Authors: Shi Can, Guo Y., Zhao Chunfa, Yang Yang, Xu ZhangAbstract:Railway Ballasted Track stiffness is an important indicator to identify supporting condition that ensures that the facility is well designed and functioned. Although many studies have been performed on Track stiffness based on experimental tests and finite-element methods, the factors influencing the Track stiffness have not been completely confirmed yet, especially the influences from ballast and subgrade layers at the mesoscopic level. To address this research gap, a combination of the discrete element method and the finite difference method model was utilized to study the factors influencing the Track stiffness from the particle level. Factors (related to ballast layer properties) are bulk density, thickness, and stiffness, and another factor (related to subgrade properties) is elastic modulus. Additionally, the relationship between the Track stiffness and the mechanical behavior of ballast was analyzed. This study quantified the influences of Track components on the Track stiffness and accordingly proposed how to improve it from the ballast and subgrade layers at the mesoscopic level, which can provide guidance for railway Ballasted Track design and maintenance. Accepted Author ManuscriptRailway Engineerin
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Analysis of Railway Ballasted Track Stiffness and Behavior with a Hybrid Discrete-Continuum Approach
'American Society of Civil Engineers (ASCE)', 2021Co-Authors: Shi Can, Guo Y., Zhao Chunfa, Yang Yang, Xu ZhangAbstract:Railway Ballasted Track stiffness is an important indicator to identify supporting condition that ensures that the facility is well designed and functioned. Although many studies have been performed on Track stiffness based on experimental tests and finite-element methods, the factors influencing the Track stiffness have not been completely confirmed yet, especially the influences from ballast and subgrade layers at the mesoscopic level. To address this research gap, a combination of the discrete element method and the finite difference method model was utilized to study the factors influencing the Track stiffness from the particle level. Factors (related to ballast layer properties) are bulk density, thickness, and stiffness, and another factor (related to subgrade properties) is elastic modulus. Additionally, the relationship between the Track stiffness and the mechanical behavior of ballast was analyzed. This study quantified the influences of Track components on the Track stiffness and accordingly proposed how to improve it from the ballast and subgrade layers at the mesoscopic level, which can provide guidance for railway Ballasted Track design and maintenance.
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Effect of sleeper bottom texture on lateral resistance with discrete element modelling
'Elsevier BV', 2020Co-Authors: Guo Y., Markine V.l., Fu Hao, Yu Qian, Jing GuoqingAbstract:The lateral stability of Ballasted Track becomes more important because of the safety requirement under the demand of higher train speed and heavier axle load. To increase the lateral resistance of ballast bed, this paper proposes three types of new sleepers, frictional sleepers. The frictional sleepers are sleepers with different shapes of textures attached at the sleeper bottom. To study the application feasibility of the frictional sleepers, experimental tests (single sleeper pull-out test) and numerical simulation (discrete element modelling) are performed. The lateral resistances of the three types of frictional sleepers are compared with the traditional sleeper based on the experimental test, and the mechanism of the lateral resistance increase is revealed according to the numerical simulation. The results indicate that the frictional sleepers can increase the lateral resistance by 32% (maximum), due to the enhanced interaction between sleeper and ballast particles. More importantly, different types of frictional sleepers have different performances, and the optimal friction sleeper is confirmed. This study is helpful for the further research on sleeper design.
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Effect of sleeper bottom texture on lateral resistance with discrete element modelling
'Elsevier BV', 2020Co-Authors: Guo Y., Markine V.l., Fu Hao, Yu Qian, Jing GuoqingAbstract:The lateral stability of Ballasted Track becomes more important because of the safety requirement under the demand of higher train speed and heavier axle load. To increase the lateral resistance of ballast bed, this paper proposes three types of new sleepers, frictional sleepers. The frictional sleepers are sleepers with different shapes of textures attached at the sleeper bottom. To study the application feasibility of the frictional sleepers, experimental tests (single sleeper pull-out test) and numerical simulation (discrete element modelling) are performed. The lateral resistances of the three types of frictional sleepers are compared with the traditional sleeper based on the experimental test, and the mechanism of the lateral resistance increase is revealed according to the numerical simulation. The results indicate that the frictional sleepers can increase the lateral resistance by 32% (maximum), due to the enhanced interaction between sleeper and ballast particles. More importantly, different types of frictional sleepers have different performances, and the optimal friction sleeper is confirmed. This study is helpful for the further research on sleeper design.Accepted Author ManuscriptRailway Engineerin
Wanming Zhai - One of the best experts on this subject based on the ideXlab platform.
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Full-scale multi-functional test platform for investigating mechanical performance of Track–subgrade systems of high-speed railways
'Springer Science and Business Media LLC', 2020Co-Authors: Wanming Zhai, Kaiyun Wang, Zhaowei Chen, Shengyang Zhu, Chengbiao Cai, Gang LiuAbstract:Abstract Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure, a full-scale multi-functional test platform for high-speed railway Track–subgrade system is developed in this paper, and its main functions for investigating the mechanical performance of Track–subgrade systems are elaborated with three typical experimental examples. Comprising the full-scale subgrade structure and all the five types of Track structures adopted in Chinese high-speed railways, namely the CRTS I, the CRTS II and the CRTS III ballastless Tracks, the double-block ballastless Track and the Ballasted Track, the test platform is established strictly according to the construction standard of Chinese high-speed railways. Three kinds of effective loading methods are employed, including the real bogie loading, multi-point loading and the impact loading. Various types of sensors are adopted in different components of the five types of Track–subgrade systems to measure the displacement, acceleration, pressure, structural strain and deformation, etc. Utilizing this test platform, both dynamic characteristics and long-term performance evolution of high-speed railway Track–subgrade systems can be investigated, being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways. As examples, three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless Track systems and for studying the long-term accumulative settlement of the Ballasted Track–subgrade system in high-speed railways. Some interesting phenomena and meaningful results are captured by the developed test platform, which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure
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dynamic behavior analysis of high speed railway ballast under moving vehicle loads using discrete element method
International Journal of Geomechanics, 2017Co-Authors: Xu Zhang, Chunfa Zhao, Wanming ZhaiAbstract:AbstractConsidering the real irregular shapes of ballast particles and complete Track skeleton, a two-dimensional discrete element model is built to investigate the dynamic behavior of high-speed railway (HSR) Ballasted Track. Taking the moving wheel loads obtained from railway vehicle-Track coupled dynamics simulation as the excitation inputs, the dynamic behavior of ballast particles in terms of contact force, stress, and vibration response are simulated using the discrete element model. Numerical results show that the ballast particles within the depth of 200 mm under sleepers would be most likely to carry a higher stress level when a vehicle passes by. Vibration amplitudes of ballast particles increase with the increase of vehicle speed, and the acceleration amplitudes rise sharply when the vehicle speed is higher than 200 km/h. Spectrum analyses indicate that the dominant frequencies of particle displacement and velocity are lower than 100 Hz, whereas the acceleration responses contain not only low-f...
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experimental investigation into ground vibrations induced by very high speed trains on a non Ballasted Track
Soil Dynamics and Earthquake Engineering, 2015Co-Authors: Wanming Zhai, Kai Wei, Xiaolin Song, Minghe ShaoAbstract:Abstract A field measurement of ground vibration was performed on the Beijing−Shanghai high-speed railway in China. In this paper, the experimental results of vertical ground vibration accelerations induced by very high speed trains running over a non-Ballasted Track on embankment with speeds from 300 to 410 km/h are reported and analyzed in detail for the first time. Characteristics of ground vibration accelerations in both time and frequency domains are analyzed based on the test data. It is shown that the periodic exciting action of high-speed train bogies can be identified in time histories of vertical accelerations of the ground within the range of 50 m from the Track centerline. The first dominant sensitive frequency of the ground vibration acceleration results from the wheelbase of the bogie, and the center distance of two neighboring cars plays an important role in the significant frequencies of the ground vibration acceleration. Variations of time–response peak value and frequency-weighted vertical acceleration level of ground vibration in relation with train speed as well as the distance from the Track centerline are also investigated. Results show that the time-domain peak value of ground vibration acceleration exhibits an approximately linear upward tendency with the increase of train speed. With the increasing distance from the Track centerline, the frequency-weighted vertical acceleration level of the ground vibration attenuates more slowly than the time-domain peak value of the ground vibration acceleration does. Severe impact of high-speed railway ground vibration on human body comfort on the ground occurs at the speed of 380–400 km/h. The results given in the paper are also valuable for validating the numerical prediction of train induced ground vibrations.
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prediction of high speed train induced ground vibration based on train Track ground system model
Earthquake Engineering and Engineering Vibration, 2010Co-Authors: Wanming Zhai, Xiaolin SongAbstract:The development of analysis on train-induced ground vibration is briefly summarized. A train-Track-ground integrated dynamic model is introduced in the paper to predict the ground vibration induced by high-speed trains. Representative dynamic responses of the train-Track-ground system predicted by the model are presented. Some major results measured from two field tests on the ground vibration induced by two high-speed trains are reported. Numerical prediction with the proposed train-Track-ground model is validated by the high-speed train running experiments. Research results show that the wheel/rail dynamic interaction caused by Track irregularities has a significant influence on the ground acceleration and little influence on the ground displacement. The main frequencies of the ground vibration induced by high-speed trains are usually below 80 Hz. Compared with the Ballasted Track, the ballastless Track structure can produce much larger train-induced ground vibration at frequencies above 40 Hz. The vertical ground vibration is much larger than the lateral and longitudinal components.
Pierreetienne Gautie - One of the best experts on this subject based on the ideXlab platform.
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slab Track review of existing systems and optimization potentials including very high speed
Construction and Building Materials, 2015Co-Authors: Pierreetienne GautieAbstract:Abstract Slab Track systems have been developed and implemented in a number of situations, including high speed, in a number of countries. A worldwide review of system types and implementations will be presented, with some focus on projects where SYSTRA was involved. Design criteria, construction techniques will be covered as well as feedback from operation for some cases. Elements and methodology for LCC assessment of some of the systems will also be included, including comparison with Ballasted Track systems in specific instances. A focus on very high speed will then identify the potential advantages of slab Track systems in that domain, but also the attention points to focus on when thinking of slab Track for very high speed, including e.g. noise questions. Finally, optimization potentials with respect to existing concepts will be presented.
