f Active Multichannel Seismic Surface Wave Method for Subsurface Cavity Detection

The Multi-channel Analysis of Surface Waves (MASW) is a recently developed seismic method to estimate S-wave velocity structure under the ground for geotechnical engineering purposes. The field setting of the survey uses a linear geophone array and a small seismic source such as sledgehammer or weight drop. It analyses the seismic waves in the frequency domain for the dispersion property of surface waves and estimates the distribution of the S-wave velocity below the surveyed area that is most responsible for the analyzed propagation velocity pattern of surface waves. After a relatively simple procedure, final Vs information is provided in 1-D, 2-D, and 3-D formats.