Compressional to shear wave velocity ratio of granular rocks: Role of rough grain contacts

1992 ◽  
Vol 19 (16) ◽  
pp. 1683-1686 ◽  
Author(s):  
Victor V. Palciauskas
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Ratio

scholarly journals The Role of Shear Wave Velocity and Non-Linearity of Soil in the Seismic Response of a Coupled Tunnel-Soil-Above Ground Building System

Geosciences ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 473 ◽  
Author(s):  
Glenda Abate ◽  
Salvatore Grasso ◽  
Maria Rossella Massimino
Keyword(s):  
Seismic Response ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Dynamic Properties ◽  
Kinematic Hardening ◽  
System Response ◽  
Flow Rule ◽  
Elastic Model

The presence of tunnels close to aboveground structures may modify the response of these structures, while the contrary is also true, the presence of aboveground structures may modify the dynamic response of tunnels. In this context, the dynamic properties of the soil through which the aboveground and underground structures are “connected” could play an important role. The paper reports dynamic FEM (Finite Element Method) analyses of a coupled tunnel-soil-above ground structure system (TSS system), which differ in regards to the soil shear wave velocity and in turns for the damping ratio, in order to investigate the role of these parameters in the full-coupled TSS system response. The analyses were performed using three different seismic inputs. Moreover, the soil non-linearity was taken into account adopting two different constitutive models: i) an equivalent linear visco-elastic model, characterized by degraded soil shear moduli and damping ratios, according to suggestions given by EC8 in 2003; and ii) a visco-elasto-plastic constitutive model, characterized by isotropic and kinematic hardening and a non-associated flow rule. The seismic response of the system was investigated in the time and frequency domains, in terms of: acceleration ratios; amplification ratios and response spectra; and bending moments in the tunnel.

Simulation of downhole and crosshole seismic tests on sand using the hydraulic gradient similitude method

1990 ◽  
Vol 27 (4) ◽  
pp. 441-460 ◽  
Author(s):  
Li Yan ◽  
Peter M. Byrne
Keyword(s):  
Wave Propagation ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Stress Ratio ◽  
Velocity Ratio ◽  
Hydraulic Gradient ◽  
Empirical Equations ◽  
Wave Measurement

A method of simulating downhole and crosshole seismic shear-wave tests in a model under controlled stress conditionsis described. The downhole and shear wave in horizontal plane (SH) crosshole shear waves are generated and received along the principal stress axes using piezoceramic bender elements. The K0in situ stress conditions, including loading and unloading stress paths, are simulated by the hydraulic gradient similitude method, which allows high stresses simulating field conditions to be obtained. The horizontal stress during the tests is directly measured by a lateral total-stress transducer. The test data are used to evaluate various published empirical equations that relate shear-wave velocity and soil stress state. It is found that although the various empirical equations can predict the in situ shear-wave velocity profile reasonably well, only the equation that relates the shear-wave velocity to the individual principal stresses in the directions of wave propagation and particle motion can predict the variation of the velocity ratio between the downhole and SH crosshole tests. It was also found that the stress ratio has some effects on the downhole (or shear wave in vertical plane (SV) crosshole) shear-wave velocity, but not on the SH crosshole shear-wave velocity. This indicates that it is only the stress ratio in the plane of wave propagation that is important to the shear-wave velocity. Comparison between the downhole and SH crosshole shows that structure anisotropy is in the order of 10%. In addjtion, K0 values are predicted from shear-wave measurement and compared with measured ones. The difficulties in obtaining K0 values from shear-wave measurement are also discussed. Key words: hydraulic gradient, model tests, downhole and crosshole shear-wave tests, sand.

scholarly journals Dispersion of Love Waves in a Composite Layer Resting on Monoclinic Half-Space

2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
Sukumar Saha
Keyword(s):  
Shear Wave ◽  
Half Space ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Ratio ◽  
Composite Layer ◽  
Love Waves ◽  
Isotropic Layer ◽  
Ratio Curve ◽  
Wave Velocity Equation

Dispersion of Love waves is studied in a fibre-reinforced layer resting on monoclinic half-space. The wave velocity equation has been obtained for a fiber-reinforced layer resting on monoclinic half space. Shear wave velocity ratio curve for Love waves has been shown graphically for fibre reinforced material layer resting on various monoclinic half-spaces. In a similar way, shear wave velocity ratio curve for Love waves has been plotted for an isotropic layer resting on various monoclinic half-spaces. From these curves, it has been observed that the curves are of similar type for a fibre reinforced layer resting on monoclinic half-spaces, and the shear wave velocity ratio ranges from 1.14 to 7.19, whereas for the case isotropic layer, this range varies from 1.0 to 2.19.

scholarly journals Passive processing of active nodal seismic data: Estimation of V<sub>P</sub> / V<sub>S</sub>-ratios to characterize structure and hydrology of an alpine valley infill

2019 ◽  
Author(s):  
Michael Behm ◽  
Feng Cheng ◽  
Anna Patterson ◽  
Gerilyn Soreghan
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Ratio ◽  
Velocity Model ◽  
P Wave ◽  
Similar Data ◽  
S Wave ◽  
Alpine Valley ◽  
Active Source

Abstract. The advent of cable-free nodal arrays for conventional seismic reflection and refraction experiments is changing the acquisition style for active source surveys. Instead of triggering short recording windows for each shot, the nodes are continuously recording over the entire acquisition period from the first to the last shot. The main benefit is a significant increase in geometrical and logistical flexibility. As a by-product, a significant amount of continuous data might also be collected. These data can be analysed with passive seismic methods and therefore offer the possibility to complement subsurface characterization at marginal additional cost. We present data and results from a 2.4 km long active source profile which has been recently acquired in Western Colorado (US) to characterize the structure and sedimentary infill of an over-deepened alpine valley. We show how the leftover passive data from the active source acquisition can be processed towards a shear wave velocity model with seismic interferometry. The shear wave velocity model supports the structural interpretation of the active P-wave data, and the P-to-S-wave velocity ratio provides new insights into the nature and hydrological properties of the sedimentary infill. We discuss the benefits and limitations of our workflow and conclude with recommendations for acquisition and processing of similar data sets.

scholarly journals Passive processing of active nodal seismic data: estimation of <i>V</i><sub>P</sub>∕<i>V</i><sub>S</sub> ratios to characterize structure and hydrology of an alpine valley infill

Solid Earth ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 1337-1354 ◽  
Author(s):  
Michael Behm ◽  
Feng Cheng ◽  
Anna Patterson ◽  
Gerilyn S. Soreghan
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Ratio ◽  
Velocity Model ◽  
P Wave ◽  
S Wave ◽  
Alpine Valley ◽  
Active Source ◽  
Passive Seismic

Abstract. The advent of cable-free nodal arrays for conventional seismic reflection and refraction experiments is changing the acquisition style for active-source surveys. Instead of triggering short recording windows for each shot, the nodes are continuously recording over the entire acquisition period from the first to the last shot. The main benefit is a significant increase in geometrical and logistical flexibility. As a by-product, a significant amount of continuous data might also be collected. These data can be analyzed with passive seismic methods and therefore offer the possibility to complement subsurface characterization at marginal additional cost. We present data and results from a 2.4 km long active-source profile, which have recently been acquired in western Colorado (US) to characterize the structure and sedimentary infill of an over-deepened alpine valley. We show how the “leftover” passive data from the active-source acquisition can be processed towards a shear wave velocity model with seismic interferometry. The shear wave velocity model supports the structural interpretation of the active P-wave data, and the P-to-S-wave velocity ratio provides new insights into the nature and hydrological properties of the sedimentary infill. We discuss the benefits and limitations of our workflow and conclude with recommendations for the acquisition and processing of similar datasets.

Role of Acoustic Shear Wave Velocity Measurement in Characterization of Breast Lesions

2013 ◽  
Vol 32 (2) ◽  
pp. 285-294 ◽  
Author(s):  
Jianqiao Zhou ◽  
Weiwei Zhan ◽  
Cai Chang ◽  
Jinwen Zhang ◽  
Zhifang Yang ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Measurement ◽  
Breast Lesions

scholarly journals Shear wave velocity and stiffness of sand: the role of non-plastic fines

Géotechnique ◽  
2018 ◽  
Vol 68 (10) ◽  
pp. 931-934 ◽  
Author(s):  
J. Yang ◽  
X. Liu ◽  
M. M. Rahman ◽  
R. LO ◽  
M. Goudarzy ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity
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