Damping of Sands for Varying Saturation

AbstractA series of resonant column tests have been performed in the torsional mode of vibration to assess the effect of saturation, starting from the near dry state to the fully saturated state, on the damping ratio of sands corresponding to the threshold strain level. Tests were carried out on three different gradations of sand for various combinations of relative density and effective confining pressure. For fine sands, a certain optimum degree of saturation exists at which the damping ratio minimizes; it is known that a decrease in Sr from a fully saturated state leads to a continuous increase in the matric suction. With an increase in the relative density, the optimum degree of saturation for fine sand increases marginally from 1.38 to 1.49%, but does not show any dependency on the effective confining pressure. In contrast, the minimum values of the damping ratio for medium and coarse sands are found to always correspond to the near dry state. The damping ratio decreases continuously with increases i...

[1]  V. Drnevich,et al.  Shear Modulus and Damping in Soils: Measurement and Parameter Effects (Terzaghi Leture) , 1972 .

[2]  Glenn J. Rix,et al.  Reduction of equipment-generated damping in resonant column measurements , 2003 .

[3]  O. Pallara,et al.  Shear Modulus and Damping of Soils , 1997 .

[4]  J. Kumar,et al.  Dynamic properties of sand from dry to fully saturated states , 2012 .

[5]  V. Drnevich,et al.  SHEAR MODULUS AND DAMPING IN SOILS: DESIGN EQUATIONS AND CURVES , 1972 .

[6]  Jyant Kumar,et al.  Effect of sample torsional stiffness on resonant column test results , 2007 .

[7]  Amos Nur,et al.  Pore fluids and seismic attenuation in rocks , 1979 .

[8]  Surendra K. Saxena,et al.  DYNAMIC MODULI AND DAMPING RATIOS FOR MONTEREY NO. 0 SAND BY RESONANT COLUMN TESTS , 1989 .

[9]  J. R. Hall,et al.  Closure of "Dissipation of Elastic Wave Energy in Granular Soils" , 1963 .

[10]  Gye-Chun Cho,et al.  UNSATURATED PARTICULATE MATERIALS--PARTICLE-LEVEL STUDIES , 2001 .

[11]  Giovanni Cascante,et al.  Flexural excitation in a standard torsional-resonant column device , 1998 .

[12]  A. W. Cresswell,et al.  Determining the maximum density of sands by pluviation , 1999 .

[13]  J. Kumar,et al.  Effect of relative density and confining pressure on Poisson ratio from bender and extender elements tests , 2010 .

[14]  Giovanni Cascante,et al.  Interparticle contact behavior and wave propagation , 1996 .

[15]  Giovanni Cascante,et al.  Resonant Column Testing: The Inherent Counter EMF Effect , 2003 .

[16]  V. Drnevich,et al.  Evaluation of Dynamic Properties of Sands by Resonant Column Testing , 1984 .

[17]  D. Negussey,et al.  RELATIVE DENSITY OF PLUVIATED SAND SAMPLES , 1984 .

[18]  Mladen Vucetic,et al.  Cyclic Threshold Shear Strains in Soils , 1994 .

[19]  J. Kumar,et al.  A note on the measurement of travel times using bender and extender elements , 2010 .

[20]  J. Kumar,et al.  On determining the elastic modulus of a cylindrical sample subjected to flexural excitation in a resonant column apparatus , 2010 .