This study was conducted to provide reliable values of the stiffness and damping properties of frozen soils subjected to vibratory loads and to define the significant factors affecting these parameters. A laboratory test was conducted on prepared specimens of frozen soils where a right circular cylinder was subjected to steady-state sinusoidal vibration. The material was considered to be linearly viscoelastic. Analysis of test data based on one-dimensional wave propagation yielded the complex Young's modulus, the complex shear modulus, the phase velocity of wave propagation, the shear velocity, the damping property expressed as the angle representing time lag between stress and strain, an attenuation coefficient, and a complex Poisson's ratio. The frequency of vibration was varied for 500 to 10,000 Hz, and the peak dynamic stress was varied from 0.1 to 5.0 psi. Specimens were remolded or cored in-situ, frozen, and tested at 0,15, and 25 F(-17.8, -9.4, and -3.9 C). A few tests were conducted on identical soils nonfrozen. Test results from a limited number of tests on selected soils indicate that the stiffness of these soils varies with the volume of ice/volume of soil ratio, and that ice is less stiff than saturated frozen soils. Frozen soils have stiffnesses up to 100 times those of identical soils nonfrozen. Depending upon the degree of ice saturation, the stiffness of non-saturated frozen soils varies from that of the saturated soils to nearly that of the nonfrozen soils. Stiffness increases with decreasing temperature but the rate is relatively low. As temperature rises and approaches the freezing point, stiffness abrupty decreases. Damping, as a property of the material does not differ greatly for frozen soil versus nonfrozen soil. This indicates that the mechanism influencing damping for frozen soil is quite different from that for nonfrozen soil. In the range of frequencies and stress studied, the use of linear biscoelastic theory appears to be adequate for frozen soils, as only slight evidence to nonlinearity was observed. /Author/

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 103 p.

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Filing Info

  • Accession Number: 00130664
  • Record Type: Publication
  • ISBN: 23
  • Report/Paper Numbers: No. 265 Tech Rpt.
  • Files: TRIS
  • Created Date: Apr 7 1976 12:00AM