Comparison of Surface-Wave Techniques in the Spatial Profiling of Subsurface Stiffness

The discrepancy among results of various surface-wave tests is reported. In Korea, universities and industries collaborated to compare the reliability of surface waves including the Spectral-Analysis-of-Surface-Waves (SASW) method, the Multichannel Analysis of Surface Waves (MASW) method, the Harmonic Wavelet Analysis of Waves method (HWAW) and the Refraction Microtremor (ReMi) method at a given geological site. The resulting shear-wave velocity profiles were compared with borehole seismic test results. Also, the stratification evaluated by surface-wave tests is compared with the stratification by borehole logs and SPT-N values. The distinct difference between the SASW and the MASW methods was identified in the depth resolution of the 1-D shear wave velocity and in the accuracy of the 2-D spatial profiling of subsurface stiffness. The effects of seismic source, the sensitivity of sensors and the forward modeling theory are discussed to explain the discrepancy between the SASW method and the MASW method.