【摘要】 基于一致粘弹性人工边界建立了有砟轨道高速铁路在动荷载作用下的三维轨道路基有限元模型,模型考虑列车荷载、钢轨、轨枕、道床及路基的接触关系,采用移动轮载单元模拟列车通过时的动力作用。分析了四种机车车辆的一个轮对荷载引起的动应力在路基中的传播特性,包括路基面动应力与轴重、车速的关系,动应力沿路基纵向、横向及深度方向的变化。通过计算结果与秦沈客运专线综合试验实测结果的比较,验证了有限元分析的可靠性。三维一致粘弹性人工边界及单元的的成功应用,对缩小计算模型、缩短计算时间和提高计算精度提供了解决方案,有利于高速铁路尤其是无砟轨道路基动力特性的进一步研究。更多还原

【Abstract】 This paper presents the experimental validation of a numerical model for the dynamic response of subgrade subjected to high-speed moving loads. The numerical model is of three-dimensional (3D) and created in the platform of ABAQUS, adopting consistent viscous-spring artificial boundaries (VSAB). It fully accounts for the dynamic interaction between the track and soil. By the introduction of viscous-spring boundary elements the computation efficiency can be improved without losing any precision.The track geometry is assumed to be invariant in the longitudinal direction and the track irregularity is considered. The model is validated through several comprehensive experiments that have been performed in the Qin-Shen passenger line. Herein, this paper analyzes the wave propagation behaviors in subgrade structure induced by the high-speed train, including the dynamic stress and the deformation of the subgrade under different speeds and wheel loads, the stress variation along the horizontal and vertical directions, and the stress attenuation with depth. The adoption of this 3D artificial boundary increases computation efficiency. The proposed model is expected to contribute to the study on the dynamic stress of non-ballast track.更多还原