HR: 0800h
AN: T51C-0701    [Abstracts]
TI: A Discrete Particle Numerical Investigation of Rock Fracture Compliance in a Multi-fracture System
AU: * Möllhoff, M
EM: martin.moellhoff@ucd.ie
AF: Seismology and Computational Rock Physics Laboratory, School of Geological Sciences, University College Dublin, Belfield, Dublin, 4, Ireland
AU: Bean, C J
EM: chris.bean@ucd.ie
AF: Seismology and Computational Rock Physics Laboratory, School of Geological Sciences, University College Dublin, Belfield, Dublin, 4, Ireland
AB: Fractures can greatly influence the elastic properties of a rock matrix and seismic wave propagation within it. Quantifying fracture properties from seismic data has the potential to assist in the understanding of many geophysical applications including the study of active fault zones, ground stability and underground waste storage. In this work we validate the time delay and attenuation characteristics of a single planar fracture modeled with a Discrete Particle Scheme (DPS) against analytical solutions. This validation opens the way to numerically investigate the effect of multiple fractures on wave propagation. We find that time delay and attenuation in sparsely fractured systems agree with analytical expressions of mean fracture compliance, while they depart significantly in densely fractured systems. Hence direct measurements of attenuation or time delays are generally not suitable to quantify fracture compliance in multi-fracture systems. However, we show that if the medium is sufficiently scattering the indirect measurement of time delays with Coda Wave Interferometry does allow for an accurate quantification of mean fracture compliance.
DE: 0550 Model verification and validation
DE: 5144 Wave attenuation
DE: 7290 Computational seismology
DE: 8010 Fractures and faults
SC: Tectonophysics [T]
MN: 2007 Fall Meeting