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Combined use of active and passive surface waves

Park, C B; Miller, R D; Rydén, Nils LU ; Xia, J and Ivanov, J (2005) In Journal of Environmental & Engineering Geophysics 10(3). p.323-334
Abstract
With a surface wave method to estimate shear-wave velocity (Vs) from dispersion curve(s) of known mode(s), accurate modal identification is obviously a crucial issue. In this regard, the dispersion imaging method is an essential processing tool as it can unfold the multi-modal nature of surface waves through direct wavetield transformations. When a combined dispersion curve of an extended frequency range is prepared from analyses of both passive and active surface waves attempting to increase the maximum depth of Vs estimation, the modal nature of the passive curve (as well as the active one) must be assessed although it has usually been considered the fundamental mode. We report two experimental survey cases performed at the same soil... (More)
With a surface wave method to estimate shear-wave velocity (Vs) from dispersion curve(s) of known mode(s), accurate modal identification is obviously a crucial issue. In this regard, the dispersion imaging method is an essential processing tool as it can unfold the multi-modal nature of surface waves through direct wavetield transformations. When a combined dispersion curve of an extended frequency range is prepared from analyses of both passive and active surface waves attempting to increase the maximum depth of Vs estimation, the modal nature of the passive curve (as well as the active one) must be assessed although it has usually been considered the fundamental mode. We report two experimental survey cases performed at the same soil site, but at two different times, employing the passive and active versions of the multichannel analysis of surface waves (MASW) method for an increased investigation depth. In the earlier survey, the modal nature of the imaged dispersion trends from the passive (<20 Hz) and active (>20 Hz) data sets was identified as the fundamental mode, whereas it was confidently re-identified as the first higher mode from the later survey. Modal inspection with the dispersion image created by combining passive and active image data sets was the key to this confident analysis. The modal nature of the passive curve was identified from its context with active curves, whose confident analysis therefore had to come first. An active data set acquired with a small (<1.0 m) receiver spacing and an impact point located close to the receivers appears important for this purpose. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Environmental & Engineering Geophysics
volume
10
issue
3
pages
323 - 334
publisher
ENVIRONMENTAL ENGINEERING GEOPHYSICAL SOCIETY
external identifiers
  • wos:000232266300009
  • scopus:26644473887
ISSN
1943-2658
language
English
LU publication?
yes
id
475f6178-9ea3-4de6-b104-e6c85b6c13f5 (old id 221379)
date added to LUP
2007-08-07 17:10:14
date last changed
2017-11-12 03:20:59
@article{475f6178-9ea3-4de6-b104-e6c85b6c13f5,
  abstract     = {With a surface wave method to estimate shear-wave velocity (Vs) from dispersion curve(s) of known mode(s), accurate modal identification is obviously a crucial issue. In this regard, the dispersion imaging method is an essential processing tool as it can unfold the multi-modal nature of surface waves through direct wavetield transformations. When a combined dispersion curve of an extended frequency range is prepared from analyses of both passive and active surface waves attempting to increase the maximum depth of Vs estimation, the modal nature of the passive curve (as well as the active one) must be assessed although it has usually been considered the fundamental mode. We report two experimental survey cases performed at the same soil site, but at two different times, employing the passive and active versions of the multichannel analysis of surface waves (MASW) method for an increased investigation depth. In the earlier survey, the modal nature of the imaged dispersion trends from the passive (&lt;20 Hz) and active (&gt;20 Hz) data sets was identified as the fundamental mode, whereas it was confidently re-identified as the first higher mode from the later survey. Modal inspection with the dispersion image created by combining passive and active image data sets was the key to this confident analysis. The modal nature of the passive curve was identified from its context with active curves, whose confident analysis therefore had to come first. An active data set acquired with a small (&lt;1.0 m) receiver spacing and an impact point located close to the receivers appears important for this purpose.},
  author       = {Park, C B and Miller, R D and Rydén, Nils and Xia, J and Ivanov, J},
  issn         = {1943-2658},
  language     = {eng},
  number       = {3},
  pages        = {323--334},
  publisher    = {ENVIRONMENTAL ENGINEERING GEOPHYSICAL SOCIETY},
  series       = {Journal of Environmental & Engineering Geophysics},
  title        = {Combined use of active and passive surface waves},
  volume       = {10},
  year         = {2005},
}