Relationship between Shear Velocities Recorded by Microtremor Observations and Seismic Cone Penetration Test Results

This research proposes a relationship between two methods such as a numerical approach by conducting a microtremor array observation and field survey by using the seismic cone penetration test unit (SCPTu). A database of shear-wave velocity (Vs) measurements was established using the microtremor array technique and seismic cone penetration test unit (SCPTu) on high-quality samples of rock and soft soil in Padang city, Indonesia. The study also demonstrates that the Vs values obtained from the different methods are consistent with the microtremor array technique. This technique may thus be deemed a valuable tool, as it can be used in engineering practice with confidence. Comparison of the Vs for different soils at the first layer between the microtremor array observation results and the SCPTu results exhibited the microtremor array method is unable to determine the Vs at the layer where its Vs changes dramatically, such as at the same layer as station UNP at 2 to 3.5m deep.

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Seismic cone penetration test and seismic tomography in permafrost

Canadian Geotechnical Journal ◽

10.1139/t04-026 ◽

2004 ◽

Vol 41 (5) ◽

pp. 796-813 ◽

Cited By ~ 19

Author(s):

Anne-Marie LeBlanc ◽

Richard Fortier ◽

Michel Allard ◽

Calin Cosma ◽

Sylvie Buteau

Keyword(s):

Seismic Tomography ◽

Dynamic Properties ◽

Cone Penetration Test ◽

The Body ◽

Body Waves ◽

Reconstruction Technique ◽

Seismic Velocities ◽

Penetration Test ◽

Cone Penetration ◽

Seismic Cone Penetration Test

Two high-resolution multi-offset vertical seismic profile (VSP) surveys were carried out in a permafrost mound near Umiujaq in northern Quebec, Canada, while performing seismic cone penetration tests (SCPT) to study the cryostratigraphy and assess the body waves velocities and the dynamic properties of warm permafrost. Penetrometer-mounted triaxial accelerometers were used as the VSP receivers, and a swept impact seismic technique (SIST) source generating both compressional and shear waves was moved near the surface following a cross configuration of 40 seismic shot-point locations surrounding each of the two SCPTs. The inversion of travel times based on a simultaneous iterative reconstruction technique (SIRT) provided tomographic images of the distribution of seismic velocities in permafrost. The Young's and shear moduli at low strains were then calculated from the seismic velocities and the permafrost density measured on core samples. The combination of multi-offset VSP survey, SCPT, SIST, and SIRT for tomographic imaging led to new insights in the dynamic properties of permafrost at temperatures close to 0 °C. The P- and S-wave velocities in permafrost vary from 2400 to 3200 m/s and from 900 to 1750 m/s, respectively, for a temperature range between 0.2 and 2.0 °C. The Young's modulus varies from 2.15 to 13.65 GPa, and the shear modulus varies from 1.00 to 4.75 GPa over the same range of temperature.Key words: permafrost, seismic cone penetration test, vertical seismic profiling, seismic tomography, dynamic properties.

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Practical aspects of in situ measurements of material damping with the seismic cone penetration test

Canadian Geotechnical Journal ◽

10.1139/t93-018 ◽

1993 ◽

Vol 30 (2) ◽

pp. 211-219 ◽

Cited By ~ 6

Author(s):

W. P. Stewart ◽

R. G. Campanella

Keyword(s):

Shear Wave ◽

Cone Penetration Test ◽

Material Damping ◽

Penetration Test ◽

Cone Penetration ◽

Seismic Shear ◽

Laboratory Results ◽

Calculation Methodology ◽

Seismic Cone Penetration Test

The downhole seismic cone penetration test (SCPT) procedure has been extended to allow the measurement of material damping at small strains at minimum expense while one is measuring shear wave velocity. The nature of damping, the required equipment characteristics, and the recommended procedure and calculation methodology are presented in a practical way. SCPT results from four different sites give results that are in general agreement with laboratory measurements of damping for sands and clays and with values recommended by other authors. It appears, however, that previously reported measurements of damping by borehole methods are higher, by a factor of two or more, when compared with SCPT and laboratory results. Key words : in situ, damping, seismic, shear wave, cone penetrometers, procedures.

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