DAMPING IN SATURATED SOIL

A mathematical model is described which predicts damping and wave velocity in water-saturated soils. Two mechanisms for energy loss are included in the model; one accounts for inelasticity of the soil skeleton in a water environment and the other for viscous losses in the pore-water as it moves relative to the skeleton. The result is damping which is frequency dependent and which depends on such parameters as porosity, grain size, permeability and effective stress. The model predicts that losses in the soil skeleton dominate at low frequencies while viscous losses due to motion of the interstitial water become predominant at higher frequencies. The terms high and low are relative, with their actual values depending on the physical properties of the particular soil being modeled. Because of the importance of pore fluid motion, results of vibration tests such as the resonant column must be carefully interpreted in order for these tests to yield results which can be used to predict attenuation in propagating waves. Since viscous losses affect both shearing and extensional motion, all the various types of test are subject to their influence. Curves are presented showing the effect on damping of various parameters such as frequency and permeability. The input for generating the curves is based on well established data already in the literature and the results suggest an explanation for some of the early test results for saturated soils that were published but never fully interpreted.

Media Info

  • Features: Appendices; Figures; References;
  • Pagination: p. 960-975

Subject/Index Terms

Filing Info

  • Accession Number: 00179791
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Oct 12 1978 12:00AM