Shear Wave Propagation in Unconsolidated Fluid Saturated Porous Media.
Abstract
Experimental shear wave speed and attenuation measurments are reported for seven laboratory sediments. The samples consisted of four sizes of well sorted glass beads and three natural sands. Measurements were obtained for both air and water saturation without application of external pressure. The speed and attenuation for each sample was determined from the change with transducer separation of the transit time and amplitude of an acoustic pulse. Broadband bender elements provided an overall frequency range of 600 Hz to 200 kHz, with individual sediment ranges of approximately a decade. The attenuation was found to vary approximately as the first power of the frequency. Various physical characteristics of the samples, for example, density and permeabilty, are reported to allow comparison of the experimental results with theoretical predictions. Supplementary compressional wave speed and attenuation measurements at the single frequency of 120 kHz are also provided. A simple viscoelastic model based on perfect coupling between the sediment grains and the pore fluid predicts the main features of the observed data. There is evidence, however, of an effect due to relative motion between the grains and the fluid. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1979
- Accession Number
- ADA072867
Entities
People
- David Warren Bell
Organizations
- University of Texas at Austin