A tentative approach based on unified asperity deformation model and effective compliance theory to explain the pressure-dependence of anisotropic velocity in sandstones

2012 ◽  
Author(s):  
Kai Gao ◽  
Fatimah Al-Ismail ◽  
Richard L. Gibson
Keyword(s):  
Pressure Dependence ◽  
Deformation Model ◽  
Effective Compliance ◽  
Asperity Deformation

Pressure-dependent seismic velocities based on effective compliance theory and an asperity deformation model

Geophysics ◽  
2012 ◽  
Vol 77 (6) ◽  
pp. D229-D243 ◽  
Author(s):  
Kai Gao ◽  
Richard L. Gibson
Keyword(s):  
Pressure Dependence ◽  
Laboratory Data ◽  
Confining Pressure ◽  
Time Lapse ◽  
Hertzian Contact ◽  
Deformation Model ◽  
Seismic Velocities ◽  
Power Law Distribution ◽  
S Wave ◽  
Effective Compliance

Seismic velocities of rocks depend strongly on confining pressure, which is often explained by the fracture compliances changes within the rocks. It is important to have an accurate model describing the relations between confining pressure and seismic velocities for applications such as time-lapse reservoir characterization. We propose a new model to address this problem by combining the existing effective compliance theory with new solutions for the pressure dependence of fracture compliances. Specifically, we assume the fracture contact surface can be represented by a set of elastic hemispheres with radii following power-law distribution, and the pressure dependence of seismic velocities can be expressed through pressure-dependent normal and tangential fracture compliances that are derived from Hertzian contact theory. Joint data fittings of P- and S-wave velocity laboratory data show that our model is accurate. We also implement fluid substitution using our model to explain the similar stress-induced velocity variations of fluid-saturated fractured rocks.

An asperity-deformation model for effective pressure

1996 ◽  
Vol 256 (1-4) ◽  
pp. 241-251 ◽  
Author(s):  
Anthony F. Gangi ◽  
Richard L. Carlson
Keyword(s):  
Deformation Model ◽  
Effective Pressure ◽  
Asperity Deformation

On the pressure dependence of the thermodynamical scaling exponent γ

Soft Matter ◽  
2020 ◽  
Vol 16 (19) ◽  
pp. 4625-4631 ◽  
Author(s):  
R. Casalini ◽  
T. C. Ransom
Keyword(s):  
Pressure Dependence ◽  
Scaling Exponent ◽  
Scaling Parameter

In materials with a constant scaling parameter γS, the Isomorph γI is found to vary with pressure, demonstrating γS ≠ γI.

PRESSURE DEPENDENCE OF THE SUPERFLUID DENSITY IN 3He-B

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-37-C6-38 ◽  
Author(s):  
C. N. Archie ◽  
T. A. Alvesalo ◽  
J. E. Bethold ◽  
J. D. Reppy ◽  
R. C. Richardson
Keyword(s):  
Pressure Dependence ◽  
Superfluid Density

PRESSURE DEPENDENCE OF PHONON LINESHAPES OF SOLlD DEUTERIUM IN THE ORDERED STATE

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-97-C6-98
Author(s):  
R. Jochemsen ◽  
V. V. Goldman ◽  
Isaac F. Silvera
Keyword(s):  
Pressure Dependence ◽  
Ordered State

GAS PHASE RAMAN SPECTRUM OF TCNQ AND PRESSURE DEPENDENCE OF THE MODES IN CRYSTALS OF TNCQ°

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-323-C6-325
Author(s):  
C. Carlone ◽  
N. K. Hota ◽  
H. J. Stolz ◽  
M. Elbert ◽  
H. Kuzmany ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Gas Phase ◽  
Pressure Dependence

PRESSURE DEPENDENCE OF IMPURITY INDUCED RAMAN SCATTERING SPECTRA I N ZnS CRYSTALS

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-743-C6-745
Author(s):  
M. Zigone ◽  
M. Vandevyver ◽  
D. N. Talwar
Keyword(s):  
Raman Scattering ◽  
Pressure Dependence ◽  
Scattering Spectra ◽  
Raman Scattering Spectra

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

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