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Environmental vibrations induced by subway operation are harmful to human health and structures when they exceed a certain value. Therefore, effective measures should be taken to reduce the noise and vibration generated by the metro. Therefore, a method to reduce the vibration by the installation of honeycomb Duxseal-cement columns under the ballast is presented in this paper. A honeycomb Duxseal-cement column was embedded in the subgrade of Qingdao Metro Line 13. A field test to measure the vibration of Qingdao Metro Line 13 was conducted. In addition, the time history curve of the vibration acceleration was obtained by processing the data and a Fourier transform was conducted for the test data to obtain a corresponding frequency spectrum curve. The spectrum curve was then converted into the one-third octave spectrum. Finally, the average value of the frequency vibration levels was determined. The comparison between the vibration generated by the metro filling and non-filling Duxseal-cement columns was investigated in detail. The test results show that the subgrade of metro in-filled by the Duxseal-cement columns obtains a better isolation effect than that of non-filling Duxseal-cement columns. The honeycomb Duxseal-cement columns present in the metros decrease their vibration accelerations in three directions, the X-, Y-, and Z-directions, by 33%, 28%, and 40%, respectively, compared with the original. • Vibration reduction effectiveness for metro by Duxseal-cement is investigated. • Field test characterized Duxseal-cement with good wave absorption capability. • Vibration characteristics of ground vibrations due to metro were analyzed. [ABSTRACT FROM AUTHOR]

In this Technical Note, a new material (i.e., Duxseal) with high damping ratio is introduced to the wave impeding block (WIB) as an active vibration isolating barrier in the free field. To evaluate the performance of the Duxseal-WIB (DXWIB), a set of field tests are performed at three test sites of Jinan-Qingdao high-speed railway of China subjected to a moving load at a high speed of 250 km/h. Accelerations in the X-, Y-, and Z-directions are monitored at multiple distances away from the track. Characteristics of ground vibrations in both time and frequency domains are analyzed using the test data. The effectiveness of DXWIB in reducing the level of ground vibration is discussed and demonstrated by comparing with the case with traditional WIB. • A new barrier Duxseal-WIB is developed to apply to high speed railway. • Excellent isolation effectiveness of Duxseal-WIB is confirmed. • Difference of effectiveness between DXWIB and traditional WIB are compared. [ABSTRACT FROM AUTHOR]