高速铁路填充沟隔振效果的2.5D有限元分析

2.5D finite element analysis of vibration isolation effect of high-speed railway filled ditch

高铁运行产生的振动对周边环境的影响不容忽视,空沟填充沟是高速铁路有效的屏障隔振方式之一。文中以饱和土2.5D有限元理论为基础,考虑轨道和路基的动力相互作用,建立轨道-路基-填充沟数值计算模型,编制FORTRAN计算程序,分析列车在低速和高速运行条件下填充沟的隔振性能及设计参数对隔振效果的影响。计算表明:填充沟对沟后区域隔振效果较好,且高速列车的隔振效果优于低速列车;隔振后振动频段范围变化不大,但原频段振动竖向加速度幅值有较明显衰减;隔振后加速度振级下降约20 dB,加速度衰减系数衰减至隔振前的0.1倍;填充沟的弹性模量、埋深以及埋置位置对隔振效果均有较大影响。

The impact of the vibration generated by high-speed rail operations on the surrounding environment cannot be ignored.Empty trenches and filled trenches are one of the effective barrier vibration isolation methods for high-speed railways.In this paper,based on the 2.5D finite element theory of saturated soil,considering the dynamic interaction between the track and the roadbed,the numerical calculation model of the track-subgrade-filled trench is established.The FORTRAN calculation program was compiled to analyze the vibration isolation performance and design parameters of the filled trench under low-speed and high-speed running conditions on the vibration isolation effect.The calculation shows that the filled trench has better vibration isolation effect in the area behind the trench,and the vibration isolation effect of the high-speed train is better than that of the low-speed train;after vibration isolation,the vibration frequency range does not change much,but the amplitude of the vertical acceleration of the original frequency band has a significant attenuation.After vibration isolation,the acceleration vibration level drops by about 20 dB,and the acceleration attenuation coefficient attenuates to one-tenth of the original;the elastic modulus,buried depth,and buried position of the filled trench have a great influence on the vibration isolation effect.