  We study the structural properties of two-dimensional granular packings
prepared by random deposition from a source line. We consider a class of random
ballistic deposition models based on single-particle relaxation rules
controlled by a critical angle, and we show that these local rules can be
formulated as rolling friction in the framework of dynamic methods for the
simulation of granular materials. We find that a packing prepared by random
deposition models is generically unstable, and undergoes dynamic
rearrangements. As a result, the dynamic method leads systematically to a
higher solid fraction than the geometrical model for the same critical angle.
We characterize the structure of the packings generated by both methods in
terms of solid fraction, contact connectivity and anisotropy. Our analysis
provides evidence for four packing regimes as a function of solid fraction, the
mechanisms of packing growth being different in each regime.
