The Parallel Seismic Technique for Determination of Foundation Pile Length

The length of existing foundation piles is unknown in many cases due to missing files and drawings. The investigation methods used in most cases today have certain limitations that require the application of new techniques. The parallel seismic method uses first arrivals of elastic waves generated by an impulse on the pile top registered by sensors in a nearby borehole. The travel time curves can be interpreted in terms of velocities and foundation depth. Numerical simulation (ray-tracing and full waveform modelling) helps to understand the results achieved at non-standard foundations or under complex subsurface conditions. The method is successfully applied in research and commercial projects.