Extraction of Body Waves from Seismic Data Induced by High-Speed Train

High-speed trains (HSTs) running on viaducts can excite seismic waves to propagate underground, shown in Figure 1, which can be regarded as a new kind of source for subsurface monitoring and imaging. The HST source can be regarded as the superposition of a series of sub-sources with different time delays. The complexity of the HST source causes the seismic data induced by HST highly interfered in the time and space. HST-induced seismic data include body waves and surface waves. Body waves contain higher frequency components and can describe the strata more precisely. However, the complexity of HST-induced seismic data makes it difficult to extract body waves. In this study, we analyze HST-induced seismic data in the F-K domain. It is found that surface waves and body waves in HST-induced data present different characteristics in the F-K domain. Combining the characteristic differences between surface waves and body waves in the F-K domain, we extract body waves through seismic interferometry method. Numerical experimental results show that body waves can be successfully extracted from HST-induced seismic data through appropriate f-k filters and band-pass filters.