中文摘要：

为研究武广高速铁路无砟轨道路基的振动特性,对武昌-咸宁综合试验段路基进行了现场实车测试。获得了各测点在不同列车荷载作用下的竖向振动加速度和动应力幅值,总结了试验段路基动力响应的分布规律,获得了试验段路基的固有频率,并结合小波分析方法对路基的振动特性进行了频域分析。结果表明,车速的提升加剧了基床表层顶面路基的振动,在260～320 km/h车速段尤为明显。经过2.7 m高路堤的衰减,路基的动力响应幅值和振动能量已基本不受车速影响。级配碎石层能有效抑制振动沿路基深度的传递。随着车速的提升,转向架固定轴距作用率、轨道不平顺成为引起路基振动的主要原因。轴重对动力响应幅值和振动能量的影响较车速更为显著,轴重的增加使得振动能量在频域内更为集中。

英文摘要：

In order to study the vibration characteristics of ballastless-track subgrade for Wuhan-Guangzhou high-speed railway,in-situ train-induced vibration tests are performed in the Huchang-Xianning test section.Magnitudes of vertical vibration acceleration and dynamic stress of all the measuring points are obtained when bullet trains units and track inspection trains run in the test section respectively.Distribution laws of dynamic response in the tested subgrade are summarized.Natural frequencies of the tested subgrade are obtained.Furthermore,incorporating wavelet analysis method,vibration characteristics of the tested subgrade are analyzed in the frequency domain.The results show that the increase in train speed enhances the vibration at the top surface of the tested subgrade,especially at 260-320 km/h.After attenuating over 2.7 m high embankment,magnitudes of dynamic response and vibration energies of the tested subgrade are very little,and the influence of train speeds is not obvious to them.The graded broken stone layer can effectively inhibit the propagation of vibration with depth in subgrade.With the increase in train speed,vibration of subgrade is mainly controlled by wheelbase and track smoothness.Axle loads effect magnitudes of dynamic response and vibration energies more significantly than train speeds.Increase in axle loads concentrates vibration energies in a more narrow frequency band.