HR: 14:35h
AN: NS43A-03    [Abstracts]
TI: Geotechnical and Petrophysical Properties of Unconsolidated Materials from Electrical Measurements
AU: * Boadu, F
EM: boadu@duke.edu
AF: Department of Civil and Environmental Engineering, Duke University, P. O Box 90287, Durham, NC 27708, United States
AB: Micro-structural modifications in unconsolidated geo-materials due to changes in effective stress affect the stability and strength of such materials. These processes often result in geo-hazards (e.g., landslides, liquefaction, debris flow) which claim so many lives, destroy the environments and cause considerable amounts of property damage. The effect of confining and pore pressure (effective stress) on the petrophysical, geotechnical as well as the electrical properties of sand-clay mixtures is investigated in a laboratory environment. Spectral electrical response (SER) measurements are performed over a range of frequencies (0.001Hz-10kHz) in a load cell connected to a transmitter-receiver unit. Useful electrical parameters are extracted from the responses and related to the relevant petrophysical/geotechnical parameters, that is, the void ratio, dry density and the modulus of elasticity. These relations can be useful in predicting the physical, mechanical and geotechnical properties of unconsolidated geo-materials in transition from frame-supported to suspensions or (from high to low effective stress). Utilization of insights and understanding gained from the laboratory measurements will be useful in achieving the ultimate goal of using non-invasive geophysical methods to monitor and assess the potential instabilities in unconsolidated geo-materials supporting sensitive structures.
DE: 1822 Geomechanics
DE: 1865 Soils (0486)
DE: 3914 Electrical properties
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly