Rayleigh wave method of measuring the frequency-dependent shear modulus

2017 ◽  
Vol 141 (5) ◽  
pp. 3832-3832
Author(s):  
Marius J. Muller ◽  
Luc Mongeau
Keyword(s):  
Shear Modulus ◽  
Rayleigh Wave ◽  
Wave Method ◽  
Frequency Dependent

The Correlation of Dynamic Cone Penetration Blow Count of Wind Carried Sand vs. Surface Wave Velocity in West Bank of Qinghai Lake

2012 ◽  
Vol 212-213 ◽  
pp. 457-460
Author(s):  
Jian Kun Liu ◽  
Jian Hong Fang ◽  
Yong Feng Hou ◽  
Jun Hua Xiao
Keyword(s):  
Rayleigh Wave ◽  
Wave Velocity ◽  
West Bank ◽  
Qinghai Lake ◽  
Wave Method ◽  
Cone Penetration ◽  
The West ◽  
Rayleigh Wave Velocity ◽  
Surface Wave Velocity ◽  
Dynamic Cone Penetration

Based on a test of wind carried sand roadbed in the west bank of Qinghai Lake, Rayleigh wave method is introduced to measure roadbed compactness of the specific soil in China, and analysis is conducted to find correlation of Rayleigh wave velocity (VR) vs. the blow count (N10) of dynamic cone penetration, then a regression formula is presented.

scholarly journals Seismic signature of turbulence during the 2017 Oroville Dam spillway erosion crisis

2018 ◽  
Author(s):  
Phillip J. Goodling ◽  
Vedran Lekic ◽  
Karen Prestegaard
Keyword(s):  
Turbulent Flow ◽  
Rayleigh Wave ◽  
Flood Control ◽  
Large Scale ◽  
Source Location ◽  
Scaling Exponent ◽  
Polarization Analysis ◽  
Frequency Dependent ◽  
Turbulent Eddies ◽  
Dependent Polarization

Abstract. Knowing the location of large-scale turbulent eddies during catastrophic flooding events improves predictions of erosive scour. The erosion damage to the Oroville Dam flood control spillway in early 2017 is an example of the erosive power of turbulent flow. During this event, a defect in the simple concrete channel quickly eroded into a chasm 47 meters deep. Erosion by turbulent flow is difficult to evaluate in real time, but near-channel seismic monitoring provides a tool to evaluate flow dynamics from a safe distance. Previous studies have had limited ability to identify source location or the type of surface wave (i.e. Love or Rayleigh wave) excited by different river processes. Here we use a single three-component seismometer method (Frequency-Dependent Polarization Analysis) to characterize the dominant seismic source location and seismic surface waves produced by the Oroville dam flood control spillway, using the abrupt change in spillway geometry as a natural experiment. We find that the scaling exponent between seismic power and release discharge is greater following damage to the spillway, suggesting larger turbulent eddies excite more seismic energy. The mean azimuth in the 5–10 Hz frequency band was used to resolve the location of spillway damage. Observed polarization attributes deviate from those expected for a Rayleigh wave, though numerical modelling indicates these deviations are explained by propagation up the hillside topography. Our results suggest Frequency-Dependent Polarization Analysis is a promising approach for locating areas of increased flow turbulence. This method could be applied to other erosion problems near engineered structures and to understanding energy dissipation, erosion, and channel morphology development in natural rivers, particularly at high discharges.

scholarly journals In vivo measurement of shear modulus of the human cornea using optical coherence elastography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Antoine Ramier ◽  
Amira M. Eltony ◽  
YiTong Chen ◽  
Fatima Clouser ◽  
Judith S. Birkenfeld ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Rayleigh Wave ◽  
Wave Speed ◽  
Critical Role ◽  
Shear Stiffness ◽  
Human Cornea ◽  
Optical Coherence ◽  
In Vivo Measurement ◽  
Rayleigh Wave Speed

Abstract Corneal stiffness plays a critical role in shaping the cornea with respect to intraocular pressure and physical interventions. However, it remains difficult to measure the mechanical properties noninvasively. Here, we report the first measurement of shear modulus in human corneas in vivo using optical coherence elastography (OCE) based on surface elastic waves. In a pilot study of 12 healthy subjects aged between 25 and 67, the Rayleigh-wave speed was 7.86 ± 0.75 m/s, corresponding to a shear modulus of 72 ± 14 kPa. Our data reveal two unexpected trends: no correlation was found between the wave speed and IOP between 13–18 mmHg, and shear modulus decreases with age (− 0.32 ± 0.17 m/s per decade). We propose that shear stiffness is governed by the interfibrillar matrix, whereas tensile strength is dominated by collagen fibrils. Rayleigh-wave OCE may prove useful for clinical diagnosis, refractive surgeries, and treatment monitoring.

scholarly journals Seismic signature of turbulence during the 2017 Oroville Dam spillway erosion crisis

2018 ◽  
Vol 6 (2) ◽  
pp. 351-367 ◽  
Author(s):  
Phillip J. Goodling ◽  
Vedran Lekic ◽  
Karen Prestegaard
Keyword(s):  
Energy Dissipation ◽  
Turbulent Flow ◽  
Rayleigh Wave ◽  
Flood Control ◽  
Large Scale ◽  
Source Location ◽  
Scaling Exponent ◽  
Polarization Analysis ◽  
Frequency Dependent ◽  
Dependent Polarization

Abstract. Knowing the location of large-scale turbulent eddies during catastrophic flooding events improves predictions of erosive scour. The erosion damage to the Oroville Dam flood control spillway in early 2017 is an example of the erosive power of turbulent flow. During this event, a defect in the simple concrete channel quickly eroded into a 47 m deep chasm. Erosion by turbulent flow is difficult to evaluate in real time, but near-channel seismic monitoring provides a tool to evaluate flow dynamics from a safe distance. Previous studies have had limited ability to identify source location or the type of surface wave (i.e., Love or Rayleigh wave) excited by different river processes. Here we use a single three-component seismometer method (frequency-dependent polarization analysis) to characterize the dominant seismic source location and seismic surface waves produced by the Oroville Dam flood control spillway, using the abrupt change in spillway geometry as a natural experiment. We find that the scaling exponent between seismic power and release discharge is greater following damage to the spillway, suggesting additional sources of turbulent energy dissipation excite more seismic energy. The mean azimuth in the 5–10 Hz frequency band was used to resolve the location of spillway damage. Observed polarization attributes deviate from those expected for a Rayleigh wave, though numerical modeling indicates these deviations may be explained by propagation up the uneven hillside topography. Our results suggest frequency-dependent polarization analysis is a promising approach for locating areas of increased flow turbulence. This method could be applied to other erosion problems near engineered structures as well as to understanding energy dissipation, erosion, and channel morphology development in natural rivers, particularly at high discharges.

High-frequency Rayleigh-Wave method

2009 ◽  
Vol 20 (3) ◽  
pp. 563-579 ◽  
Author(s):  
Jianghai Xia ◽  
Richard D. Miller ◽  
Yixian Xu ◽  
Yinhe Luo ◽  
Chao Chen ◽  
...  
Keyword(s):  
Rayleigh Wave ◽  
High Frequency ◽  
Wave Method
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