Snapshots of stress fields before and at the point of failure for case R
a=3×107, θ=16, a=0.75, T
=6.6×105. Time sequence goes from left to right and top to bottom. White arrows show velocities. (a) and (b) are close to beginning of simulation, (c) is at the mid-point between the start and failure, and (d-i) are right before overturning (depicted in (j-l)) occurs.