A pitfall in shallow shear-wave refraction surveying

Xia, Jianghai; Miller, Richard D.; Park, Choon B.; Wightman, Ed; Nigbor, Robert L.

doi:10.1016/s0926-9851(02)00197-0

Cited by 85 publications

(56 citation statements)

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“…Errors in S-wave velocities obtained using the MASW method are 15% or less and random when compared with direct borehole measurements (XIA et al, 2002a). Other studies include repeatability of MASW (BEATY and SCHMITT, 2003), delineation of bedrock , near-surface quality factors (Q) (XIA et al, 2002b), a pitfall using shear-wave refraction surveying (XIA et al, 2002c), detection of voids (XIA et al, 2004(XIA et al, , 2007a, the MASW method using a fast and efficient method for geophone deployment-autojuggie (STEEPLES et al, 1999;TIAN et al, 2003a b), a unified workflow for geotechnical and engineering seismology (YILMAZ et al, 2006), discussion of MASW dispersion characteristics (LIN and CHANG, 2004), optimized selection of fielddata-acquisition parameters (XU et al, 2006, XIA et al, 2006a in press), estimation of S-wave velocities for a continuous earth model (XIA et al, 2006b), generation of a dispersion image using slant stacking (XIA et al, 2007b) and a s-p transform (LUO et al, 2008b), generation of a pseudo-2D shear-wave velocity section by inversion of a series of 1D dispersion curves (LUO et al, 2008a), numerical modeling of surface waves , discussion of surface-wave inversion with a high-velocity-layer intrusion model (CALDERóN-MACíAS and LUKE, 2007), and a lowvelocity-layer intrusion model (LU et al, 2007;LIANG et al, 2008). Dispersions of ground-penetrating radar data were also inverted for the subsurface material properties (KRUK et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Data-resolution Matrix and Model-resolution Matrix for Rayleigh-wave Inversion Using a Damped Least-squares Method

Xia

Miller²,

Xu³

2008

Pure appl. geophys.

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Inversion of multimode surface-wave data is of increasing interest in the near-surface geophysics community. For a given near-surface geophysical problem, it is essential to understand how well the data, calculated according to a layered-earth model, might match the observed data. A data-resolution matrix is a function of the data kernel (determined by a geophysical model and a priori information applied to the problem), not the data. A data-resolution matrix of high-frequency (C2 Hz) Rayleigh-wave phase velocities, therefore, offers a quantitative tool for designing field surveys and predicting the match between calculated and observed data. We employed a data-resolution matrix to select data that would be well predicted and we find that there are advantages of incorporating higher modes in inversion. The resulting discussion using the data-resolution matrix provides insight into the process of inverting Rayleigh-wave phase velocities with higher-mode data to estimate S-wave velocity structure. Discussion also suggested that each near-surface geophysical target can only be resolved using Rayleigh-wave phase velocities within specific frequency ranges, and higher-mode data are normally more accurately predicted than fundamental-mode data because of restrictions on the data kernel for the inversion system. We used synthetic and real-world examples to demonstrate that selected data with the data-resolution matrix can provide better inversion results and to explain with the data-resolution matrix why incorporating higher-mode data in inversion can provide better results. We also calculated model-resolution matrices in these examples to show the potential of increasing model resolution with selected surface-wave data.

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Section: Introductionmentioning

confidence: 99%

Data-resolution Matrix and Model-resolution Matrix for Rayleigh-wave Inversion Using a Damped Least-squares Method

Xia

Miller²,

Xu³

2008

Pure appl. geophys.

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“…The use of SH waves is preferable as they do not convert in other wave types in correspondence of horizontal interfaces between soils with different seismic rigidity, decreasing the uncertainties of other seismic techniques (Mc Cornack et al 1984;Stümpel et al 1984;Milkereit et al 1986;Gasperini et al 1994;Blair and Korringa 1987). The occurrence in the seismograms of converted waves generated by not horizontal interfaces (Xia et al 2002), has been prevented by using the cross-over acquisition procedure (Rainone et al 2009). In presence of granular and porous deposits, the use of SH waves is advantageous because they are unaffected by saturation, show a lower attenuation in unsaturated media and are less influenced by saturation (Nur and Simmons 1969;Signanini and Torrese 2004;Winkler and Núr 1982).…”

Section: Seismic Refraction and Reflection Surveymentioning

confidence: 99%

Italian accelerometric archive: geological, geophysical and geotechnical investigations at strong-motion stations

Luzi

Lovati

D’Alema

et al. 2009

Bull Earthquake Eng

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Geological, geophysical and geotechnical investigations, for the characterization of the strong-motion recording sites managed by the Italian Civil Protection, have been carried out in the framework of the project "Italian strong-motion database in the period 1972-2004". The project aimed at creating an updated database of strong-motion data acquired in Italy by different institutions in the time span 1972-2004, and at improving the quality of disseminated data. This article illustrates the state of the recording site characterization before the beginning of the project, explains the criteria adopted to select the sites where geophysical/geotechnical investigation have been performed and describes the results of the promoted field surveys

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“…A shallow SH-wave refraction survey had failed in defining S-wave velocities so a surface wave survey was conducted (Xia et al, 2002b). Surface-wave data were collected using 48 8-Hz vertical-component geophones on an interval of 0.9 m, with the nearest offset of 1.8 m, with the seismic source being a 6.3-kg hammer vertically impacting on a metal plate.…”

Section: Real-world Examplesmentioning

confidence: 99%

“…To confirm the inverted S-wave velocity from the MASW method, a borehole was drilled on the site and suspension logged (Figure 3c). In the range of 0-6 m, the average difference between S-wave velocities estimated from the MASW method and those measured from suspension logging is less than 15% (Xia et al, 2002b). (5) 1153 (3) We inverted the Rayleigh-wave data again using the algorithm developed in the previous Sections.…”

Section: Real-world Examplesmentioning

confidence: 99%

Estimation of Elastic Moduli in a Compressible Gibson Half-space by Inverting Rayleigh-wave Phase Velocity

Xia

Miller

et al. 2006

Surv Geophys

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A Gibson half-space model (a non-layered Earth model) has the shear modulus varying linearly with depth in an inhomogeneous elastic half-space. In a half-space of sedimentary granular soil under a geostatic state of initial stress, the density and the Poisson's ratio do not vary considerably with depth. In such an Earth body, the dynamic shear modulus is the parameter that mainly affects the dispersion of propagating waves. We have estimated shear-wave velocities in the compressible Gibson half-space by inverting Rayleigh-wave phase velocities. An analytical dispersion law of Rayleigh-type waves in a compressible Gibson halfspace is given in an algebraic form, which makes our inversion process extremely simple and fast. The convergence of the weighted damping solution is guaranteed through selection of the damping factor using the Levenberg-Marquardt method. Calculation efficiency is achieved by reconstructing a weighted damping solution using singular value decomposition techniques. The main advantage of this algorithm is that only three parameters define the compressible Gibson half-space model. Theoretically, to determine the model by the inversion, only three Rayleigh-wave phase velocities at different frequencies are required. This is useful in practice where Rayleigh-wave energy is only developed in a limited frequency range or at certain frequencies as data acquired at manmade structures such as dams and levees. Two real examples are presented and verified by borehole S-wave velocity measurements. The results of these real examples are also compared with the results of the layered-Earth model.

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A pitfall in shallow shear-wave refraction surveying

Cited by 85 publications

References 4 publications

Data-resolution Matrix and Model-resolution Matrix for Rayleigh-wave Inversion Using a Damped Least-squares Method

Data-resolution Matrix and Model-resolution Matrix for Rayleigh-wave Inversion Using a Damped Least-squares Method

Italian accelerometric archive: geological, geophysical and geotechnical investigations at strong-motion stations

Estimation of Elastic Moduli in a Compressible Gibson Half-space by Inverting Rayleigh-wave Phase Velocity

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