列车对融土路基的振动影响（英文）

Vibration impact of trains on thawed soil subgrade

主要介绍了现场实测得到的列车交会对融土路基的振动影响。铁道机车车辆的活动可能引起轨道上部结构的振动,并以噪声和振动的形式表现出来。列车荷载和速度的增加将会导致路基动态振动效应的显著增长。由于这种接触引起的铁路轨道不均匀残余变形累积强度的增加,不仅会影响路基,也会对建筑及构筑物结构产生影响。采用土工合成材料设计轨道上部结构的目的是为了减少振动的消极影响。根据现场研究的结果和分析研究,可以得到以下结论:在长列车通过期间,铁路路基土体的振动过程具有复杂的随机性,并在其全部3个组件中伴随有很强的低谐波和中谐波;交会列车在垂直平面上引起解冻路基的优先振动;与夏季相比,路基内部正融层和边界处湿度的存在导致了振动幅值平均增大1.5~2倍,在路基承载能力计算时,必须注意这部分显著增长的振动影响;与融化的土体相比,路基内部和外部的振动分布通过一个衰减不太激烈的相关性指数δ2进行描述;在距离轨道轴线5~7m的位置,振动幅值的阻尼在水平横向上的发生率为72%~84%;该研究首次发现,路堤处路基振动幅值的阻尼小于路堑处。

This paper mainly presents the field studies of vibration impact from passing trains on the roadbed melting ground.The movement of railway rolling stock may cause oscillations on track superstructure,which manifest themselves in the form of noise and vibration.The increasing loads and speeds of trains lead to significant increases of dynamic vibration effects on the roadbed.The accumulated intensity of uneven residual deformation of railway track increases as a result that affects not only on roadbed,but also on constructions of buildings.The geosynthetics were used to design the superstructure for reducing the negative impact of vibration.The results show that during the passage of long train,the vibration process of railway subgrade soil has complex randomness,and it is accompanied by strong low harmonic and mid harmonic in all three components.Two trains passing by each other may cause preferential oscillation on the vertical plane of thawing subgrade.Compared with summer,subgrade thawing layer and boundary humidity lead to the average amplitude of vibration increasing 1.5to 2times,this part of significant growing vibration effect must be pay attention to when calculating the bearing capacity of subgrade.Compared with the melted soil,vibration distributions of inside and outside of subgrade can be described by means of a less attenuated exponential correlation.At the distance from 5to 7 mto the track axis,the damping rate of vibration amplitude is 72%to 84%in the horizontal transverse direction.It is found for the first time that the damping amplitude of subgrade at the embankment is less than that in the cut.