Self-adaptive method for high frequency seismic surface wave method

摘要: Abstract When the high frequency multi-channel analysis of surface waves (MASW) method is conducted to explore soil properties in vadose zone, existing rules for selecting near offset and spread lengths cannot satisfy requirements planar dominant Rayleigh all frequencies interest will inevitably introduce far field effects as well spatial aliases at certain frequencies. To solve these problems, a self-adaptive developed determine dispersion trends. In this method, an initial curve obtained by fixed-offset MASW used estimate wavelengths interest. At each frequency, are then set be 0.2–0.6 2–4 respectively. other words, corresponding wavelength. Furthermore, order avoid minimize number sensors or sensor locations, variable spacing configuration proposed, which first 120 steps 0.5 cm next 40 start with 1 cm followed incremental subsequent step. study, accelerometer was detect vibrations generated electrodynamic shaker operating chirp mode. Two tests were results from fixed-offset, self-adaptive, methods compared. The study demonstrates ability preferentially identify trends either fundamental mode higher modes waves. It also found that can determined beyond source range due nonlinear generate harmonics This phenomenon deserves future investigation.