  We propose a two-dimensional geometrical model, based on the concept of
geometrical frustration, conceived for the study of compaction in granular
media. The dynamics exhibits an interesting inverse logarithmic law that is
well known from real experiments. Moreover we present a simple dynamical model
of $N$ planes exchanging particles with excluded volume problems, which allows
to clarify the origin of the logarithmic relaxations and the stationary density
distribution. A simple mapping allows us to cast this Tetris-like model in the
form of an Ising-like spin systems with vacancies.
