SciTech Connect

Title: Comparing geophysical measurements to theoretical estimates for soil mixtures at low pressures

Comparing geophysical measurements to theoretical estimates for soil mixtures at low pressures The authors obtained good estimates of measured velocities of sand-peat samples at low pressures by using a theoretical method, the self-consistent theory of Berryman (1980), using sand and porous peat to represent the microstructure of the mixture. They were unable to obtain useful estimates with several other theoretical approaches, because the properties of the quartz, air and peat components of the samples vary over several orders of magnitude. Methods that are useful for consolidated rock cannot be applied directly to unconsolidated materials. Instead, careful consideration of microstructure is necessary to adapt the methods successfully. Future work includes comparison of the measured velocity values to additional theoretical estimates, investigation of Vp/Vs ratios and wave amplitudes, as well as modeling of dry and saturated sand-clay mixtures (e.g., Bonner et al., 1997, 1998). The results suggest that field data can be interpreted by comparing laboratory measurements of soil velocities to theoretical estimates of velocities in order to establish a systematic method for predicting velocities for a full range of sand-organic material mixtures at various pressures. Once the theoretical relationship is obtained, it can be used to estimate the soil composition at various depths from field measurements of seismic velocities. Additional refining of the more » method for relating velocities to soil characteristics is useful for development inversion algorithms. « less
Authors: ; ; ; ;
Publication Date:
OSTI Identifier:8169
Report Number(s):UCRL-JC-132893; EW45100000
EW45100000; TRN: AH200117%%122
DOE Contract Number:W-7405-ENG-48
Resource Type:Conference
Data Type:
Resource Relation:Conference: Environmental and Engineering Geophysical Society Symposium on the Application of Geophysics to Engineering and Environmental Problems, Oakland, CA (US), 03/14/1999--03/18/1999; Other Information: PBD: 15 Jan 1999
Research Org:Lawrence Livermore National Lab., CA (US)
Sponsoring Org:USDOE Office of Environmental Management (EM) (US)
Country of Publication:United States
Language:English
Subject: 01 COAL, LIGNITE, AND PEAT; 58 GEOSCIENCES; ALGORITHMS; GEOPHYSICS; MICROSTRUCTURE; MIXTURES; PEAT; QUARTZ; REFINING; SAND; SOILS; VELOCITY