中文摘要：

针对武广高铁无碴轨道红粘土路堑基床的动力稳定性问题,在现场进行基床动响应测试,获得了振动速度、振动加速度、动应变、动应力最大值及其在竖向及横向测试断面上的变化规律。探讨了竖直深度、水平距离、行车线路、轨道类型对路堑基床动响应的影响。结果表明：动响应随深度增加近似按指数函数衰减,随水平距离的增加按倒＂V＂字形（右线车）或近似按指数函数变化（左线车）;右线车作用下动响应大于左线车;无碴轨道基床具有不同于有碴轨道的动响应特征：无碴轨道基床动响应小于有碴轨道,动响应随深度的衰减速率慢,影响深度大,测试数据离散性小。分析表明,4个动响应参数在竖向及横向测试断面上的变化规律基本一致,且动应力与振动加速度之间具有很好的线性相关性。对比发现,本文测试数据与国外无碴轨道基床动响应测试成果具有较好的一致性,说明本文测试方案及测试成果是正确合理的。研究成果对我国高速铁路无碴轨道路堑基床的设计、施工及其动响应研究具有重要的参考价值。

英文摘要：

In view of the dynamic stability of red-clay cutting bed under the ballastless track of Wuhan-Guangzhou high-speed railway,the maximal test values and the varying regulations of dynamic velocity,dynamic acceleration,dynamic strain and dynamic stress in vertical and transverse testing sections are obtained through dynamic response tests.The influences of the vertical depth,horizontal distance,traffic lines and types of railway tracks to the dynamic response of the cutting bed are discussed.The dynamic response attenuates with the depth increase by exponential function approximately,varies with the horizontal distance increase by reverse ＂V＂ shaped for train running on the right line or by exponential function approximately for left line;The dynamic response for right line is bigger than that for left line;The ballastless track bed is of its own dynamic response characteristics which are different from those of ballasted track： dynamic responses of cutting bed under ballastless track are less than those of ballasted track,and the attenuation rate for the formers is slower,the affecting depth is bigger and data discreteness is smaller than those for the latter.The varying regulations of four dynamic response parameters in vertical and transverse testing sections are consistent basically,and there is a good linear correlation between dynamic stress and dynamic acceleration.The study results have important reference values for the design and the construction and the dynamic response study of cutting bed under ballastless track of high speed railway in China.