Rayleigh Wave Phase Velocity Extracted. Time - Frequency Analysis

Rayleigh wave exploration is a new seismic exploration method for low layer in these years rised. The method applies to many aspects widely, such as engineering prospecting, rock-soil engineering, evaluating groundsill. It's main idea that making use of frequency dispersion of Rayleigh wave to reveal geology structure of low layer. Rayleigh wave exploration is divided into steady state way and transient state way according to the differ of explode mode. At present, people adopt transient method mostly.People mostly choose traditional Fourier transform to process surface wave data anciently. Traditional Fourier transform is whole transform and can't reflect signal's local characteristic that is our needing. In this paper, we adopt time-frequency analysis method to process data, this method has a advantage that it can reflect the changing of time and frequency at mean time. Moreover, we analyze the frequency dispersion of Rayleigh wave firstly, then we introduce the two methods of surface wave exploration. We adopt traditional Fourier transform and time-frequency analysis to process data respectively. Afterwards we testify that the program is reasonable and time-frequency analysis method is feasible, in point and reliable through calculating surface wave exploration theoretical model and comparing the processing result of the two methods. Finally we obtain obvious effect by the processing of many practical data, and further demonstrate the accuracy and the practicability of the time-frequency analysis, and the method has the better apply effect and development foreground.