Non-destructive measurement of soil liquefaction density change by crosshole radar tomography, Treasure Island, California
A ground penetrating radar (GPR) experiment at the Treasure Island Test Site [TILT] was performed to non-destructively image the soil column for changes in density prior to, and following, a liquefaction event. The intervening liquefaction was achieved by controlled blasting. A geotechnical borehole radar technique was used to acquire high-resolution 2-D radar velocity data. This method of non-destructive site characterization uses radar trans-illumination surveys through the soil column and tomographic data manipulation techniques to construct radar velocity tomograms, from which averaged void ratios can be derived at 0.25 - 0.5m pixel footprints. Tomograms of void ratio were constructed through the relation between soil porosity and dielectric constant. Both pre- and post-blast tomograms were collected and indicate that liquefaction related densification occurred at the site. Volumetric strains estimated from the tomograms correlate well with the observed settlement at the site. The 2-D imagery of void ratio can serve as high-resolution data layers for numerical site response analysis.
Citation Information
Publication Year | 2000 |
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Title | Non-destructive measurement of soil liquefaction density change by crosshole radar tomography, Treasure Island, California |
DOI | 10.1061/40523(298)3 |
Authors | Robert E. Kayen, Walter A. Barnhardt, Scott Ashford, Kyle Rollins |
Publication Type | Book |
Publication Subtype | Conference publication |
Index ID | 70033610 |
Record Source | USGS Publications Warehouse |