Ultrasonic Characterization Of Synthetic Soils For Application To Near Surface Geophysics

Berge, Patricia A.; Bonner, B.P.; Boro, C.O.; Hardy, E. D.; Ruddle, C; Trombino, C.N.

doi:10.3997/2214-4609-pdb.202.1999_051

Cited by 6 publications

(14 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The water content was obtained from the water retention curve (Bonner et al, 2001). Velocity results and related uncertainties are described in detail elsewhere (Bonner et al, 1997(Bonner et al, , 1999a(Bonner et al, , 2000(Bonner et al, , 2001Aracne-Ruddle et al, 1998Berge et al, 1999 (Figure 4). Comparison of our laboratory velocity results to available seismic reflection and refraction data (e.g., Crouse et al, 1993;Taylor and Wilson, 1997;Bachrach et al, 1998;Boulanger et al, 1998;Steeples et al, 1999) showed agreement between velocities measured in the lab and field for soils of similar types, at lab pressures equivalent to the appropriate depth for the field measurements.…”

Section: Vp and Vs Results For Sands And Sand-clay Mixtures From The mentioning

confidence: 99%

“…To this end, we describe state-of-the-art laboratory experiments involving the measurement of ultrasonic velocities at low pressures in unconsolidated sediments and summarize the main velocity results. The on-going experiments at Stanford University and Lawrence Livermore National Laboratory (LLNL) were developed to make accurate measurements of compressional-wave (Vp, Qp) and shear-wave (Vs, Qs) velocities and attenuations in highly-attenuating soils at low pressures (e.g., Aracne-Ruddle et al, 1998;Bonner et al, 1999aBonner et al, , 2000Bonner et al, , 2001Zimmer et al, 2002a;2002b;Prasad, 2002). The data presented here include LLNL uniaxial measurements on dry, saturated, and partiallysaturated sands and sand-clay mixtures made at pressures below approximately 0.1 MPa;…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

14. Laboratory Measurements of Velocity and Attenuation in Sediments

Prasad¹,

Zimmer²,

Berge³

et al. 2005

Near-Surface Geophysics

View full text Add to dashboard Cite

Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P-and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P-and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P-and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand-clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0-0.1 MPa and 0.1-20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P-and S-wave velocity-dependence in dry sands around a fourth root (0.23-0.26) with the pressure dependence for S-waves being slightly lower. The P-velocity-dependence in wet sands lies around 0.4. The Vp-Vs and the Qp-Qs ratios together can be useful tools to distinguish between different lithologies and between pressure and saturation effects. These experimental velocities at the frequency of measurement (200 kHz) are slightly higher that Gassmann's (Gassmann, 1951) static result. For low pressures under uniaxial stress, Vp and Vs were a few hundred meters per second with velocities showing a strong dependence on packing, clay content, and microstructure. We provide a typical shallow soil scenario in a clean sand environment and reconstruct the velocity profile of such a sediment packet.

show abstract

Section: Vp and Vs Results For Sands And Sand-clay Mixtures From The mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

14. Laboratory Measurements of Velocity and Attenuation in Sediments

Prasad¹,

Zimmer²,

Berge³

et al. 2005

Near-Surface Geophysics

View full text Add to dashboard Cite

show abstract

“…The laboratory velocity data collected using recently-developed techniques include uniaxial measurements of ultrasonic velocities for dry, saturated, and partially-saturated sands and sand-clay mixtures made at pressures below approximately 0.1 MPa (Aracne-Ruddle et al, 1999;Berge et al, 1999;Bonner et al, 1999Bonner et al, , 2001. We also used data from Wildenschild et al (2000) for electrical properties for sand and sand-clay mixtures measured using the fourelectrode method.…”

Section: Methodsmentioning

confidence: 99%

“…Laboratory measurements of porosity, permeability, and complex impedance in the frequency range of 0.01 to 100 kHz are available for fully-saturated artificial soils made from mixtures of Ottawa sand and Wyoming bentonite, the same artificial soils for which we have ultrasonic velocity measurements (Berge et al, 1999;Bonner et al, 1999Bonner et al, , 2001Zimmer et al, 2001;Wildenschild et al, 2000). In previous work (Bertete-Aguirre and , we developed an inversion algorithm for inferring soil composition given seismic compressional (P) and shear (S) wave velocities, using laboratory ultrasonic velocity measurements to constrain the mapping from velocities to lithology.…”

Section: Introductionmentioning

confidence: 99%

Using Laboratory Measurements of Electrical and Mechanical Properties to Assist Interpretation of Field Data from Shallow Geophysical Measurements

Bertete-Aguirre¹,

Berge²,

Roberts³

2002

Symposium on the Application of Geophysics to Engineering and Environmental Problems 2002

View full text Add to dashboard Cite

Reconstruction of shallow subsurface structure from geophysical data is a central problem for many environmental and engineering applications. We observe that for shallow soil distributions, seismic data alone or electrical data alone may provide a good reconstruction of the subsurface. We show that using joint seismic and electrical data will improve the reconstruction of shallow structure. Our results emphasize that the availability of techniques for making laboratory measurements of ultrasonic velocities at low pressures in unconsolidated materials and the ability to measure complex impedance in similar samples are key elements of this approach.

show abstract

“…In this paper, we use compressional-wave velocity (Vp) and shear-wave velocity (Vs) data for artificial soils at low pressures. The data (Figure 1, Figure 2, Figure 3, and Figure 4) were collected using a recently-developed technique (Bonner et al, 1999a) for uniaxial measurements of ultrasonic velocities for dry, saturated, and partially-saturated soils at pressures below approximately 0.1 MPa (Trombino, 1998Berge et al, 1999;Bonner et al, 1999b, Zimmer et al, 2001. The laboratory measurements were made at pressures between 0 and about 0.1 MPa (about 16 psi) in pressure increments of about 0.01 MPa (about 1.5 psi), and represent the top few meters of the subsurface.…”

Section: Laboratory Datamentioning

confidence: 99%