Estimation of rippability and excavation conditions from seismic velocity measurements

McCann, D. M.; Fenning, P. J.

doi:10.1144/gsl.eng.1995.010.01.29

Cited by 11 publications

(5 citation statements)

References 10 publications

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“…The connection between V p and erodibility is supported by studies that quantify the relationship between rock strength and P-wave velocity (e.g. McCann and Fenning, 1995;Clarke and Burbank, 2010). However, there are limitations.…”

Section: Relative Rock Strength: Methods and Resultsmentioning

confidence: 91%

Resistant rock layers amplify cosmogenically‐determined erosion rates

Darling

Whipple

Bierman

et al. 2020

Earth Surf Processes Landf

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Prior numerical modeling work has suggested that incision into sub‐horizontal layered stratigraphy with variable erodibility induces non‐uniform erosion rates even if base‐level fall is steady and sustained. Erosion rates of cliff bands formed in the stronger rocks in a stratigraphic sequence can greatly exceed the rate of base‐level fall. Where quartz in downstream sediment is sourced primarily from the stronger, cliff‐forming units, erosion rates estimated from concentrations of cosmogenic beryllium‐10 (10Be) in detrital sediment will reflect the locally high erosion rates in retreating cliff bands. We derive theoretical relationships for threshold hillslopes and channels described by the stream‐power incision model as a quantitative guide to the potential magnitude of this amplification of 10Be‐derived erosion rates above the rate of base‐level fall. Our analyses predict that the degree of erosion rate amplification is a function of bedding dip and either the ratio of rock erodibility in alternating strong and weak layers in the channel network, or the ratio of cliff to intervening‐slope gradient on threshold hillslopes. We test our predictions in the cliff‐and‐bench landscape of the Grand Staircase in southern Utah, USA. We show that detrital cosmogenic erosion rates in this landscape are significantly higher (median 300 m/Ma) than the base‐level fall rate (~75 m/Ma) determined from the incision rate of a trunk stream into a ~0.6 Ma basalt flow emplaced along a 16 km reach of the channel. We infer a 3–6‐fold range in rock strength from near‐surface P‐wave velocity measurements. The approximately four‐fold difference between the median 10Be‐derived erosion rate and the long‐term rate of base‐level fall is consistent with our model and the observation that the stronger, cliff‐forming lithologies in this landscape are the primary source of quartz in detrital sediments. © 2020 John Wiley & Sons, Ltd.

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Section: Relative Rock Strength: Methods and Resultsmentioning

confidence: 91%

Resistant rock layers amplify cosmogenically‐determined erosion rates

Darling

Whipple

Bierman

et al. 2020

Earth Surf Processes Landf

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“…Based on this, from the velocity model and previous knowledge of the stratigraphy of the study area, it is possible to determine the thickness of the soil and the weathering layer, and the depth of the unweathered rock. SRT is also a suitable tool to determine the rippability of materials since there is a high contrast between the P-wave velocity (V p ) in Quaternary deposits, weathered and unweathered materials (Hunt, 1986;McCann and Fenning, 1995;Caterpillar Inc., 2000). Based on the seismic velocity chart for a D-10 bulldozer by Caterpillar (Caterpillar Inc., 2000), shown in Fig.…”

Section: Seismic Refraction Tomographymentioning

confidence: 99%

“…ERT is an investigation method that provides an electrical resistivity model of the subsurface based on the assessment of the voltage generated in the subsoil by passing an electrical current along many different paths (Barker, 1997). Variations in resistivity values are associated with changes in soil properties, such as its mineral composition, weathering and/or fracturing degree, fluid content, porosity, water saturation degree and lithology (Robinson and Coruh, 1988;Loke, 2004;Nawawi et al, 2010;Olona et al, 2010;Obi, 2012). A higher weathering and/or fracturing degree usually implies an increase in the clay content, so the material would have less electrical resistivity.…”

Section: Electrical Resistivity Tomographymentioning

confidence: 99%

Seismic refraction and electrical resistivity tomographies for geotechnical site characterization of two water reservoirs (El Hierro, Spain)

Fernández‐Baniela¹,

Arias

Rubio-Ordóñez

2021

Near Surface Geophysics

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On El Hierro (Canary Islands, Spain), the company Gorona del Viento El Hierro S.A. carried out the construction of a Wind-Pumped Hydro Power Station in order to achieve the energy autonomy on the island through 100% renewable energy. The station consists of two man-made water reservoirs, whose design was adapted to the island topography and emplaced in a valley and an inactive crater. In order to study the subsurface of both reservoirs, the characteristic heterogeneity of volcanic materials was taken into account. Therefore, a research campaign combining different methods was proposed; mechanical investigations traditionally applied in engineering (rotary boreholes, dynamic probing super heavy tests and pits) and geophysical methods (seismic refraction tomography and electrical resistivity tomography) were both utilized. The aims were to determine the geological structure of each site, detect possible anomalies or structures (i.e., faults, volcanic cavities, etc.), identify the different lithologies, determine the soil thickness and depth to bedrock, predict the excavatability of the materials, and obtain data about the physical properties and mechanical behaviour of the ground in an effort to carry out a geotechnical site characterization of both sites. At the site of the upper reservoir, electrical resistivity tomography recorded a high thickness of low resistivity soils, which were subsequently investigated by deep boreholes in order to sample and test them properly, since they could generate high settlements during the construction of the reservoir. At the site of the lower reservoir, the existing palaeorelief in the basaltic bedrock was detected by seismic refraction tomography, which allowed for the selection of the appropriate excavation machinery for the planned earthworks. The geological interpretation of the P-wave velocity models and electrical resistivity models are shown in this paper, as well as a correlation between geotechnical parameters and geophysical properties of volcanic materials and recent deposits, which will be useful for other civil projects which may be carried out in the future at sites with similar geological conditions.

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“…With the standard approach, a physical relationship using the single attribute of seismic velocity is employed to predict the petrophysical property of rock strength or fracturing over a 2D line or 3D volume (McCann et al, 1990;McCann and Fenning, 1995). Frequently, the physical relationship is semiquantitative, with lower seismic velocities indicating lower rock strength or increased fracturing.…”

Section: Seismic-refraction Attributesmentioning

confidence: 99%

14. Characterizing the near Surface with Detailed Refraction Attributes

Palmer

2010

Advances in Near-Surface Seismology and Ground-Penetrating Radar

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The tomographic inversion of near-surface seismicrefraction traveltime data is fundamentally nonunique. It is possible to generate tomograms, which range from the geologically improbable to the very detailed, all of which accurately satisfy the traveltime data. A comparison of the starting models with the final tomograms demonstrates that refraction tomography usually does not improve lateral resolution significantly. Therefore, if important geotechnical features are to be delineated, it is essential that they be included in the starting model, especially zones with low seismic velocities. Suitable detailed starting models for both traveltime and full-waveform inversion can be derived using a suite of parameters, generally known as seismic attributes. Refraction attributes can be computed readily from all near-surface seismic-refraction traveltimes, amplitudes, and waveforms, using the generalized reciprocal method (GRM) and the refraction convolution section (RCS). Furthermore, refraction attributes can be employed as a priori information to resolve nonuniqueness before the acquisition of any a posteriori information, such as borehole or other geophysical data. Narrow and wide zones with low seismic velocities are delineated with detailed attributebased tomograms and are consistent with other refraction attributes derived from head-wave amplitudes and the RCS. Those zones are not detected with refraction tomograms which use low-resolution starting models, such as the smooth vertical velocity gradient. Additional models of the near surface, such as scaled density ratios and the P-wave modulus, can be computed from combinations of the refraction attributes. The use of a suite of attributes and combined attributes as well as the seismic velocity facilitates derivation of more comprehensive quantitative models of the near surface and thus more effective integration of seismic with borehole and other geotechnical data, using either multivariate geostatistics or full-waveform inversion.

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Estimation of rippability and excavation conditions from seismic velocity measurements

Cited by 11 publications

References 10 publications

Resistant rock layers amplify cosmogenically‐determined erosion rates

Resistant rock layers amplify cosmogenically‐determined erosion rates

Seismic refraction and electrical resistivity tomographies for geotechnical site characterization of two water reservoirs (El Hierro, Spain)

14. Characterizing the near Surface with Detailed Refraction Attributes

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