| With the rapid development of urban transportation at this stage,the vibration generated by the train operation has caused many inconveniences to the normal work and daily life of the residents in the sensitive area.Some sections of the track generate large vibration due to the high speed of the train or in the curved section,the track has wave wear and other special conditions,which seriously interferes with the life of the residents and complaints occur from time to time.In this paper,in order to study the vibration of the linear section of the underground line of the urban express rail,suitable measurement points are selected to analyze the vibration damping effect of vibration damping measures by comparing the maximum Z vibration level(VLZmax)of the tunnel wall with the corresponding ordinary whole roadbed;the vibration acceleration level and ground vibration of the rail,roadbed and tunnel wall of the measurement points are analyzed to get the vibration propagation attenuation;finally,the following conclusions are obtained.（1）After the time domain analysis,the effective value of vibration acceleration of the tunnel wall of the three vibration damping measures is smaller than the corresponding ordinary whole roadbed,and the vertical vibration acceleration of the tunnel wall of the steel spring floating plate is the smallest,and the peak factor of some measurement points is greater than6.It is necessary to consider the quadratic vibration dose value（VDV）as an additional evaluation of the degree of human annoyance to vibration.（2）After the 1/3 octave analysis of the data,the vibration damping measures of the urban express rail all have good effects.The vibration damping effect of the double-layer non-linear vibration damping fasteners,vibration damping pad floating plate and steel spring floating plate of the urban express rail is 7.3d B,16.2d B and 19.7d B respectively.（3）The spectrum analysis of the measured data from the six test sections on the ground shows that the peak spectrum of vibration damping measures is mainly distributed at 50-63Hz.The double-layer nonlinear vibration damping fasteners have good vibration damping effect at 50-160 Hz,and the vibration damping pad floating plate has obvious vibration damping effect at 6-60 Hz,with vibration amplification phenomenon.（4）vibration pad floating plate rail vibration acceleration RMS value is higher than the comparison of ordinary overall bed,may be due to vibration feedback to the rail because of vibration damping track. |
