Shear Bands: Two Layer ModelsRoberto Weinberg, Monash University, Australia Ryo Anmasan, University of Tsukuba, Japan 
Copyright 20052009 by Roberto Weinberg. All rights reserved. Unlimited permission to copy or use is hereby granted for nonprofit driven enterprise subject to inclusion of this copyright notice and my World Wide Web URL: users.monash.edu.au/~weinberg. We would very much appreciate an email stating how this material will be used. Thanks, RW. 
MODEL SET UP
The model is a horizontal plane at a fixed lithostatic pressure (p), fluid absent and is deformed in pure shear with a horizontal shortening axis. The bulk modulus, K, and shear modulus G are such that they yield a Poisson ratio n
Figure 1. Model 17: study of stress distribution in a layered system, the embedded layer in the middle has elastic moduli (Shear and Bulk Moduli) an order of magnitude higher than surroudings.
A) State step 75000 
B) Mean stress
distribution 
C)
Mean stress profile (zoom in a 400m profile) 
Figure 2. Model 18: study of stress distribution in a layered system, the embedded layer in the middle has elastic moduli (Shear and Bulk Moduli) an order of magnitude lower than surroudings.
A) State step 75000 
B) Mean stress
distribution 
C)
Mean stress profile (zoom in a 400m profile) 
Figure 3. Model 20. Like Figure 2 but pore fluids are initially at twice hydrostatic pressure. Step 55000. A) State. Much narrower and numerous shear bands develop compared to the case with no fluids (Fig. 1). Click on figure for movies. B) Is a zoom of a shear band
A) State (movie) 
B) Zoom of A) plus flow
vectors 
C) Pore pressure (movie)

D) Pore pressure profile
(movie) 
E) Mean stess 
F) Mean stress profile
(movie) 
G) Volume Flux 
H) Volume Flux Profile 