水位变化对无砟轨道路基变形特性影响的研究

Model Test on Deformation Characteristics of Slab Track-subgrade under Changes of Water Level

在地下水位变化等干湿循环作用下,高速铁路路基中含水量和饱和度发生变化,加剧了路基在列车移动荷载作用下的累积变形,影响路基的长期服役性能。本文采用足尺物理模型试验,研究多次水位变化情况下高速铁路无砟轨道路基的变形特性,获得轨道板弹性变形以及路基累积变形的发展规律。本文研究表明,轨道结构弹性变形会受到列车运行速度、列车轮轴荷载振动次数和水位变化等综合因素的影响。路基地下水位第一次循环变化极大加剧了路基的累积变形,而多次循环下路基累积变形变化较小。最后对路基累积变形实测结果进行拟合,得出路基累积变形随轮轴荷载振动次数以及列车运行速度的变化规律。

The water contents and degrees of saturation of subgrade of high-speed railways change under the ac-tion of wetting-drying cycles such as variations of water level,which intensifies accumulated deformations of slabs under moving loads of trains and then deteriorates the long-term serviceability of subgrade.The paper in-troduced a full-scale model test on deformation characteristics of ballastless track-subgrade under repeated changes of water level.The law of development of elastic deformations of slabs and accumulated deformations of subgrade were presented.The research results show as follows：Elastic deformations of the slab structure are affected by train speeds,loading cycles and changes of water level;the first wetting-drying cycle caused by the change of water level greatly increases the accumulated deformations of subgrade,but the later repeated wet-ting-drying cycles have little influence.At last,the development of accumulated deformations versus numbers of cyclic loading and train speeds was concluded by fitting the measured accumulated deformations.