The center vortex model for the infrared sector of Yang-Mills theory,
previously studied for the SU(2) gauge group, is extended to SU(3). This model
is based on the assumption that vortex world-surfaces can be viewed as random
surfaces in Euclidean space-time. The confining properties are investigated,
with a particular emphasis on the finite-temperature deconfining phase
transition. The model predicts a very weak first order transition, in agreement
with SU(3) lattice Yang-Mills theory, and also reproduces a consistent behavior
of the spatial string tension in the deconfined phase. The geometrical
structure of the center vortices is studied, including vortex branchings, which
are a new property of the SU(3) case.Comment: 22 pages, 12 figures (30 eps-files), uses LaTeX package "psfrag