Phase-scanning approach to correct time-shift inaccuracies in the surface-wave walk-away method

Summary, in English

In order to maintain lateral resolution while maximizing investigation depth in a multichannel surface wave method, it is beneficial to implement the walk-away approach by using a relatively short receiver spread. Combined walk-away records, however, normally suffer from time-shift inaccuracies that adversely influence the subsequent dispersion imaging process. Time-shift inaccuracies produce phase discontinuities which can generate false apparent higher modes in the dispersion images misleading the correct interpretation of the dispersion curve. To minimize these adverse effects, we present a phase-scanning approach that searches for an optimum phase shift to correct the phase shift generated by the walk-away method. Results obtained from synthetic and real-world field data show that for the specific case of a single dominating mode the proposed approach reduces the distortions in the dispersion image caused by the walk-away approach. The proposed method is especially efficient in the presence of ambient random noise. (C) 2010 Elsevier Ltd. All rights reserved.

• Author: Edwin Obando; Choon B. Park; Nils Rydén; Peter Ulriksen
• Department/s: Engineering Geology
• Publishing year: 2010
• Language: English
• Pages: 1528-1539
• Publication/Series: Soil Dynamics and Earthquake Engineering
• Volume: 30
• Issue: 12
• Links: http://dx.doi.org/10.1016/j.soildyn.2010.07.006
• Document type: Journal article
• Publisher: Elsevier
• Topic: Geotechnical Engineering
• Status: Published
• ISBN/ISSN/Other: ISSN: 0267-7261