Surface-wave data were collected at the Yuma Proving Ground (YPG) test facility to estimate shear wave velocity using multi-channel analysis of surface waves (MASW). Rayleigh-wave attenuation versus frequency curves were calculated and inverted for shear wave quality factor, Qs. During processing, certain stations created instabilities in the Q-inversion, or produced values that were unrealistic (i.e. minimal or zero attenuation). Therefore, the initial shot gathers were transformed into the FK domain and filtered using higher mode dispersion curves (removing/attenuating the higher-mode energy) to create another set of Qs estimates. The filtered data successfully produced lower Qs estimates without inversion instabilities. The comparison of these results suggest that attenuating higher mode surface wave energy can produce more reliable Qs estimates.
Presentation Date: Tuesday, October 18, 2016
Start Time: 10:45:00 AM
Presentation Type: ORAL