Influence of source characteristics on the uncertainties in masw survey

Abstract

Multichannel Analysis of Surface Waves (MASW) method is extremely popular to carry out seismic site characterization. However, certain uncertainties are existent in this technique. One of the crucial factors which contribute to these uncertainties is the source parameters such as source type, energy and position. This study examined how the change in these parameters influences the uncertainties in the MASW method using numerical simulations. The parameters considered in the numerical simulations are the amplitude of impulse load, duration of impulse load and source offset. For the study, the results of full wave-field simulation were compared with those of plane Rayleigh wave simulation. Results indicate that the change in the amplitude of the impulse load doesn’t affect the underestimation of the Rayleigh wave phase velocity. Longer the pulse duration, better the dispersion curve observed at lower frequencies. An increment in the source offset reduces the underestimation. © 2019 Associazione Geotecnica Italiana, Rome, Italy.