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Title: Linear and Nonlinear Ultrasonic Properties of Granular Soils

Linear and Nonlinear Ultrasonic Properties of Granular Soils The ultrasonic pulse transmission method (100-500 kHz) was adapted to measure compressional (P) and shear (S) wave velocities for synthetic soils fabricated from quartz-clay and quartz-peat mixtures. Velocities were determined as samples were loaded by small (up to 0.1 MPa) uniaxial stress to determine how stress at grain contacts affects ave amplitudes, velocities, and frequency content. Samples were fabricated from quartz sand mixed with either a swelling clay or peat (natural cellulose). P velocities in these dry synthetic soil samples were low, ranging from about 230 to 430 m/s for pure sand, about 91 to 420 m/s for sand-peat mixtures, and about 230 to 470 m/s for dry sand-clay mixtures. S velocities were about half of the P velocity in most cases, about 130 to 250 m/s for pure sand, about 75-220 m/s for sand-peat mixtures, and about 88-220 m/s for dry sand-clay mixtures. These experiments demonstrate that P and S velocities are sensitive to the amount and type of admixed second phase at low concentrations. They found that dramatic increases in all velocities occur with small uniaxial loads, indicating strong nonlinearity of the acoustic properties. Composition and grain packing contribute to the mechanical response at grain contacts and the more » nonlinear response at low stresses. « less
Authors: ; ; ; ; ; ;
Publication Date:
OSTI Identifier:791377
Report Number(s):UCRL-JC-136207
TRN: US200206%%30
DOE Contract Number:W-7405-Eng-48
Resource Type:Conference
Data Type:
Resource Relation:Conference: Materials Research Society Meeting, San Francisco, CA (US), 04/24/2000--04/28/2000; Other Information: PBD: 20 Apr 2000
Research Org:Lawrence Livermore National Lab., CA (US)
Sponsoring Org:USDOE Office of Defense Programs (DP) (US)
Country of Publication:United States
Language:English
Subject: 58 GEOSCIENCES; 36 MATERIALS SCIENCE; CELLULOSE; CLAYS; MIXTURES; PEAT; QUARTZ; SAND; SHEAR PROPERTIES; SOILS; STRESSES; SWELLING; ULTRASONIC TESTING; SEISMIC P WAVES; SEISMIC S WAVES