HR: 09:30h
AN: T41F-07    [Abstracts]
TI: Stresses and deformation around fault tips and their implications for fault rupture and propagation
AU: Baker, J W
EM: bakerjw@stanford.edu
AF: Stanford University, Terman Engineering Center, #240 Stanford University, Stanford, CA 94304, United States
AU: * Borja, R I
EM: borja@stanford.edu
AF: Stanford University, Terman Engineering Center, #240 Stanford University, Stanford, CA 94304, United States
AB: Stresses and deformation around fault tips are predictors of impending fault rupture and direction of propagation. In mountain building they affect the topography of sites where Earth faults at some finite depth but the fault does not cut through the surface. Fault tips are highly damaged fracture process zones where slip builds up at a rapid pace. In this work we use various simulation techniques for quantifying stresses and deformation around fault tips, including the assumed enhanced strain, nonlinear contact mechanics, and the extended finite element methods. Enhancements of the finite element description of deformation field are critical for the contact mechanics and extended finite element methods, and to this end we use linear elastic fracture mechanics to enhance the description of the deformation field around fault tips. We investigate the impact of fault tip enhancements on the predicted magnitude and distribution of slip not only around the tip but throughout the length of the fault. Finally, we use information on stresses and deformation fields around fault tips to develop mathematical criteria for fault propagation under mode II shearing. The latter mode of deformation is critical for thrust faulting typically responsible for generating asymmetric anticlines.
DE: 8010 Fractures and faults
DE: 8012 High strain deformation zones
DE: 8020 Mechanics, theory, and modeling
SC: Tectonophysics [T]
MN: 2007 Fall Meeting