The design theories of the ballastless track in the world are reviewed in comparison with the innovative research achievements of high-speed railway ballastless track in China.The calculation methods and parameters co...The design theories of the ballastless track in the world are reviewed in comparison with the innovative research achievements of high-speed railway ballastless track in China.The calculation methods and parameters concerning train load,thermal effect,and foundation deformation of high-speed railway ballastless track,together with the structural design methods are summarized.Finally,some suggestions on the future work are provided.展开更多
According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks stru...According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks structure should be adopted preferentially in the subgrade section of high-speed railway, which is conducive to the construction, prolongation of service life and maintenance of the ballastless track. Based on the finite element model, the dynamic performance, structural strength and stability of double-block ballastless track under high earthquake-intensity action are analyzed. The analysis shows that the relative displacement between the base slab of ballastless track and the subgrade may occur under 9 degree earthquake action. A new CRTS double-block ballastless track structure with a concave-convex structure between the base slab and the subgrade is proposed in the subgrade section, and its additional stress and relative displacement under earthquake are analyzed. The results show that the additional stress and relative displacement of the new ballastless track structure and the subgrade under 9-degree earthquake actions are small, which meet the high stability requirements of high-speed railway.展开更多
Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a ...Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus.It is then compared to the performance of a ballasted track.First,slab and ballasted track models are developed to replicate the full-scale testing of track sections.Once the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track results.The slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the models.Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical speeds.Various train loading methods are discussed,and the most practical approach is retained and described.Moreover,correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards.It is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.展开更多
In order to make further study on the mechanical property of CRTSIII type slab non-ballast track structures,which was self-designed in China,based on the method of the multiscale finite element model(FEM),the traditio...In order to make further study on the mechanical property of CRTSIII type slab non-ballast track structures,which was self-designed in China,based on the method of the multiscale finite element model(FEM),the traditional FEM of slab non-ballast track structures was improved.The multiscale FEM of CRTSII type slab nonballast track structures was established based on the general finite element program ABAQUs.Then the comparative calculation was made between various FEMs,showing that the high solution precision,fast modelling speed and high solution efficiency could be obtained.Therefore,the multiscale FEM was suitable for the parametric study on mechanical behaviour of CRTSII type slab non-ballast track structures,and then the key influence factor and constructions could be optimized.展开更多
为研究道床板上拱对无砟轨道结构性能和行车品质的影响,建立含道床板上拱的列车-轨道系统振动分析伤损模型,编制FORTRAN计算程序并进行模型验证。基于车轨系统空间振动分析理论,分别计算4种道床板上拱类型的双块式无砟轨道在高速列车作...为研究道床板上拱对无砟轨道结构性能和行车品质的影响,建立含道床板上拱的列车-轨道系统振动分析伤损模型,编制FORTRAN计算程序并进行模型验证。基于车轨系统空间振动分析理论,分别计算4种道床板上拱类型的双块式无砟轨道在高速列车作用下的空间振动响应,分析比较此系统振动响应随道床板上拱类型,不平顺幅值及车速的影响规律,并对道床板上拱伤损评级。研究结果表明:各种道床板上拱类型的车轨系统动力响应均随运行速度和不平顺幅值的提升而增大。速度相同时,考虑了复合不平顺和离缝的上拱类型4的车轨系统振动响应最大,而仅考虑高低不平顺的上拱类型1的车轨系统振动响应最小。车速300 km/h时,高程偏差为11 mm的道床板上拱类型1引起的车体垂向振动加速度、轮轨作用力,脱轨系数和轮重减载率峰值分别为0.918 m/s2,100.740 k N,0.305和0.255;而类型4依次为2.037 m/s2,185.219 k N,12.503和1.727。上述机理和数据可为道床板上拱伤损评级提供参考。展开更多
基金supported by the National Natural Science Foundation of China (No. 51008258)the Fundamental Research Funds for the Central Universities (No. SWJTU09BR038)
文摘The design theories of the ballastless track in the world are reviewed in comparison with the innovative research achievements of high-speed railway ballastless track in China.The calculation methods and parameters concerning train load,thermal effect,and foundation deformation of high-speed railway ballastless track,together with the structural design methods are summarized.Finally,some suggestions on the future work are provided.
基金supported by China Railway Eryuan Engineering Group Co.,Ltd。
文摘According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks structure should be adopted preferentially in the subgrade section of high-speed railway, which is conducive to the construction, prolongation of service life and maintenance of the ballastless track. Based on the finite element model, the dynamic performance, structural strength and stability of double-block ballastless track under high earthquake-intensity action are analyzed. The analysis shows that the relative displacement between the base slab of ballastless track and the subgrade may occur under 9 degree earthquake action. A new CRTS double-block ballastless track structure with a concave-convex structure between the base slab and the subgrade is proposed in the subgrade section, and its additional stress and relative displacement under earthquake are analyzed. The results show that the additional stress and relative displacement of the new ballastless track structure and the subgrade under 9-degree earthquake actions are small, which meet the high stability requirements of high-speed railway.
基金Engineering and Physical Sciences Research Council (EPSRC) is also acknowledged for funding this work under Grant Number EP/N009207/1.
文摘Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus.It is then compared to the performance of a ballasted track.First,slab and ballasted track models are developed to replicate the full-scale testing of track sections.Once the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track results.The slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the models.Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical speeds.Various train loading methods are discussed,and the most practical approach is retained and described.Moreover,correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards.It is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.
基金supported by“111”Project(B18062)Fundamental Research Funds for the Central Universities(2019CDQYTM028).
文摘In order to make further study on the mechanical property of CRTSIII type slab non-ballast track structures,which was self-designed in China,based on the method of the multiscale finite element model(FEM),the traditional FEM of slab non-ballast track structures was improved.The multiscale FEM of CRTSII type slab nonballast track structures was established based on the general finite element program ABAQUs.Then the comparative calculation was made between various FEMs,showing that the high solution precision,fast modelling speed and high solution efficiency could be obtained.Therefore,the multiscale FEM was suitable for the parametric study on mechanical behaviour of CRTSII type slab non-ballast track structures,and then the key influence factor and constructions could be optimized.
文摘为研究道床板上拱对无砟轨道结构性能和行车品质的影响,建立含道床板上拱的列车-轨道系统振动分析伤损模型,编制FORTRAN计算程序并进行模型验证。基于车轨系统空间振动分析理论,分别计算4种道床板上拱类型的双块式无砟轨道在高速列车作用下的空间振动响应,分析比较此系统振动响应随道床板上拱类型,不平顺幅值及车速的影响规律,并对道床板上拱伤损评级。研究结果表明:各种道床板上拱类型的车轨系统动力响应均随运行速度和不平顺幅值的提升而增大。速度相同时,考虑了复合不平顺和离缝的上拱类型4的车轨系统振动响应最大,而仅考虑高低不平顺的上拱类型1的车轨系统振动响应最小。车速300 km/h时,高程偏差为11 mm的道床板上拱类型1引起的车体垂向振动加速度、轮轨作用力,脱轨系数和轮重减载率峰值分别为0.918 m/s2,100.740 k N,0.305和0.255;而类型4依次为2.037 m/s2,185.219 k N,12.503和1.727。上述机理和数据可为道床板上拱伤损评级提供参考。
