Mitigation of high-speed train-induced environmental ground vibrations considering open trenches in the soft soil conditions by in-situ tests

This study focuses on the use of open trench wave barriers to prevent undesired high-speed train-induced ground vibrations. A series of full-scale passive isolation tests are performed in the most unfavorable geotechnical conditions at the highest speed passage of the actual moving load on the elevated embankment in resonance case. For this purpose, Sakarya-Pamukova has been considered the target test area of the Istanbul-Ankara HST line in North-Western Turkey. Site-specific acceleration time-histories, both response and frequency spectra in all directions were obtained from the ground motions recorded simultaneously in the far free-field conditions with and without passive isolation applications. In particular, the variation of the surface vibrations perpendicular to the railway line with the trench effect was observed according to the insertion loss in decibels. Results indicated that the peak values of measured velocity time-histories and spectral velocity response at ground surface decrease remarkable in the transversal vibration direction with passive isolation method, even in superficial depth of the open trench. The data measured at the most unfavorable geo-dynamic conditions will contribute to the development of more cost-effective, environmentally friendly and efficient vibration isolation barriers for researchers.