Blind field tests to determine Rayleigh wave velocity on a high-speed railway environment: The reliability of seismic surface waves methods

To ensure track stability and good earthwork performance for high-speed railways the surface wave velocity in earthworks should exceed train’s speed. Specifications rail are now stating minimum Rayleigh (V R ) velocities to be checked during construction. This requires suitable reliable geophysical tests, however there no defined standards or data collection processing protocols. Additionally, analysis of these traditionally relies on practice experience those undertaking work which can introduce variability results. paper presents results a blind comparison trial investigating Multichannel Analysis Surface Waves test (MASW) use compliance evaluation, concentrating assessment ). Testing was undertaken by four companies, at same site natural ground stabilised embankment. Defined tests protocols their own design against specification assess V were used. The anonymised show reasonable agreement dispersive character soil if higher modes carefully considered when picking dispersion curve. then investigated depth using rule thumb. Such an approach avoids inversion step (to get more traditional Vs depth) potentially introduces variability. suggests that direct could used engineers give routine required further investigation areas concern within overall earthwork.