scholarly journals Combined P- and S-Wave Measurements by Seismic Dilatometer Test (SPDMT): A Case History in Bondeno (Emilia Romagna, Italy)

2019 ◽  
Vol 43 (2) ◽  
pp. 20180233 ◽  
Author(s):  
Sara Amoroso ◽  
Cesare Comina ◽  
Diego Marchetti
Keyword(s):  
Case History ◽  
S Wave ◽  
Wave Measurements

scholarly journals Effectiveness of in situ P-wave measurements in monuments: examples from Greece

2000 ◽  
Vol 22 ◽  
Author(s):  
B. Christaras
Keyword(s):  
Modulus Of Elasticity ◽  
Building Stone ◽  
P Wave ◽  
Mechanical Anisotropy ◽  
Laboratory Measurements ◽  
S Wave ◽  
Wave Velocities ◽  
Wave Measurements ◽  
Made In

P and S wave velocities can be used for both in situ and laboratory measurements of stones. These methods are used for studying such properties as mechanical anisotropy and modulus of elasticity. In this paper, the P-wave velocities were used for the estimation of the depth of weathered or artificially consolidated layers as well as the depth of cracks developed at the surface of the building stone. This estimation was made in relation to the lithology and texture of the materials, given that in many cases different lithological data create similar diagrams. All tests were carried out on representative monuments in Greece.

Seismic vertical transversely isotropic parameter inversion from P- and S-wave cross-borehole measurements in an aquifer environment

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. D101-D116
Author(s):  
Julius K. von Ketelhodt ◽  
Musa S. D. Manzi ◽  
Raymond J. Durrheim ◽  
Thomas Fechner
Keyword(s):  
Transversely Isotropic ◽  
P Wave ◽  
Perturbation Equation ◽  
S Wave ◽  
P Waves ◽  
Data Set ◽  
Near Surface ◽  
S Waves ◽  
Wave Measurements ◽  
Wave Splitting

Joint P- and S-wave measurements for tomographic cross-borehole analysis can offer more reliable interpretational insight concerning lithologic and geotechnical parameter variations compared with P-wave measurements on their own. However, anisotropy can have a large influence on S-wave measurements, with the S-wave splitting into two modes. We have developed an inversion for parameters of transversely isotropic with a vertical symmetry axis (VTI) media. Our inversion is based on the traveltime perturbation equation, using cross-gradient constraints to ensure structural similarity for the resulting VTI parameters. We first determine the inversion on a synthetic data set consisting of P-waves and vertically and horizontally polarized S-waves. Subsequently, we evaluate inversion results for a data set comprising jointly measured P-waves and vertically and horizontally polarized S-waves that were acquired in a near-surface ([Formula: see text]) aquifer environment (the Safira research site, Germany). The inverted models indicate that the anisotropy parameters [Formula: see text] and [Formula: see text] are close to zero, with no P-wave anisotropy present. A high [Formula: see text] ratio of up to nine causes considerable SV-wave anisotropy despite the low magnitudes for [Formula: see text] and [Formula: see text]. The SH-wave anisotropy parameter [Formula: see text] is estimated to be between 0.05 and 0.15 in the clay and lignite seams. The S-wave splitting is confirmed by polarization analysis prior to the inversion. The results suggest that S-wave anisotropy may be more severe than P-wave anisotropy in near-surface environments and should be taken into account when interpreting cross-borehole S-wave data.

Determining formation S-wave transverse isotropy from borehole flexural-wave dispersion data

Geophysics ◽  
2017 ◽  
Vol 82 (2) ◽  
pp. D47-D55 ◽  
Author(s):  
Song Xu ◽  
Xiao-Ming Tang ◽  
Yuan-Da Su ◽  
Sheng-Qing Lee ◽  
Chun-Xi Zhuang
Keyword(s):  
Transverse Isotropy ◽  
Transversely Isotropic ◽  
Wave Dispersion ◽  
Flexural Wave ◽  
Stoneley Wave ◽  
S Wave ◽  
Acoustic Logging ◽  
Wave Measurements ◽  
Dispersion Data ◽  
Ti Media

Many earth formations are characterized as transversely isotropic (TI) media. In acoustic logging through a vertical borehole, the S-wave TI property has traditionally been determined from borehole monopole Stoneley-wave measurements, but the feasibility of shear-TI estimation from dipole flexural waves has not been fully investigated. We have developed a methodology to determine the TI parameters from borehole dipole-flexural wave data. Our analysis shows that the Stoneley wave is sensitive to the TI property mainly in an acoustically slow formation, and the sensitivity diminishes when the formation becomes faster. The advantage of the flexural wave over the Stoneley wave is that the former wave is sensitive to the TI property in the slow and fast formations, provided the wave measurement is made in a broad frequency range in which the flexural-wave dispersion characteristics from low to high frequencies can be used. By calculating the theoretical flexural-wave dispersion curve for the TI formation and using it to fit the measured wave dispersion data, we can simultaneously determine the vertical and horizontal S-wave velocities, from which the S-wave TI parameter is obtained. Application of our methodology to field data processing shows that the TI parameter estimated from the flexural wave is almost identical to that from the Stoneley wave for a slow formation. For a fast formation, the flexural-wave result is more accurate and reliable compared with the Stoneley-wave result. Our study, thus, introduces a novel application of dipole acoustic logging.

Seismicity in the Rangely, Colorado, area: 1962-1970

1973 ◽  
Vol 63 (5) ◽  
pp. 1557-1570 ◽  
Author(s):  
James F. Gibbs ◽  
John H. Healy ◽  
C. Barry Raleigh ◽  
John Coakley
Keyword(s):  
Seismic Data ◽  
Water Injection ◽  
Seismic Energy ◽  
Seismic Signal ◽  
Oil Field ◽  
P Wave ◽  
S Wave ◽  
Uinta Basin ◽  
Wave Measurements

abstract Seismic data recorded for a 7-year period at the Uinta Basin Observatory were searched for earthquakes originating near an oil field at Rangely, Colorado, 65 km ESE of the observatory. Changes in the number of earthquakes recorded per year appear to correlate with changes in the quantity of fluid injected per year. Between November 1962 and January 1970, 976 earthquakes were detected near the oil field by the UBO station; 320 earthquakes were larger than magnitude 1. Richter local magnitudes are estimated from both S-wave and P-wave measurements; a method based on the duration of the seismic signal is used to estimate the magnitude of the larger shocks. Magnitude of the two largest shocks was 3.4 and 3.3. The total seismic energy released was 1017 ergs. During this same period, the energy used for water injection, measured at the wellhead, was 1021 ergs.

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