高速列车在高架桥软土地基段引起的地面振动监测分析

Test and analysis of soft ground vibration induced by high-speed trains on viaduct

为了解高速列车在通过软土地区高架桥段所引起的软土地基振动特性及振动波在软土中的传播衰减规律,对广深高速列车通过软土高架桥段时引起的地面三方向振动进行了监测。结果显示：地面振动的主要频率集中在5~60 Hz,各监测点速度三分量的最大值并不总是同时出现。同时,场地条件的变化对地面三方向振动,特别是两水平方向振动产生较大的影响。据此提出在美国联邦交通署的振级公式中用振动速度三分量＂矢量和＂代替单分量。代替后的结果显示：和速度所引起的振动持时呈＂漏斗状＂减小,评价结果更为合理。

In soft soil area,the ground vibration induced by high-speed train on viaduct is widely concerned.Since the Pearl River Delta is abundant of soft soil,high-speed railway is often constructed in the form of viaduct.In order to understand the vibration characteristics of soft soil and the attenuation rule of the vibration wave propagating in soft soil,triaxial vibration monitoring was made on the soft soil foundation of the GuangShen intercity high-speed train.The results show that the dominant frequency of the ground vibration is 5-60 Hz,the maximum value of each velocity component didn＇t appear at the same time.The variation of site conditions had large impacts on the triaxial vibration and more significant impact on the horizontal vibration.In this paper,vector sum of three axes vibration velocities was used instead of single velocity component for the vibration level formula（proposed by American Federal Railroad Administration）.The result shows that the duration time of the vibration attenuate is slow like a funnel,which is more reasonable to reflect the characteristics of the ground vibration.