Predicting the Geological Structure Ahead of a Tunnel Using Full Waveform Inversion - A Blind Test

Looking ahead of a tunnel is an important issue in order to have a smooth and safe construction process. Seismic methods are used to locate the geological anomalies ahead of a tunnel; the waves reflected from the geological changes carry information about the location and mechanical properties of the objects. Different migration techniques and first arrivals of the reflected waves are commonly used to achieve the goal. Full waveforms carry more information about the geological structure of a domain than the first traveltimes of the reflected waves. This work emerges from the curiosity to see whether full waveforms can successfully image the velocity field in tunnel applications. There are two parties in this study. The first party chooses a synthetic model and provides the second party with the precisely calculated waveforms in the time domain. The second party has no prior information about the synthetic model except for the waveforms and the inversion is carried out in the frequency domain as a blind test. The aim is to see whether the velocity field can be successfully imaged with the full waveform inversion.