  KASCADE-Grande is a large detector array dedicated for studies of high-energy
cosmic rays in the primary energy range from 100 TeV to 1 EeV. The
multi-detector concept of the experimental set-up offers the possibility to
measure simultaneously various observables related to the electromagnetic,
muonic, and hadronic air shower components. The experimental data are compared
to predictions of CORSIKA simulations using high-energy hadronic interaction
models (e.g. QGSJET or EPOS), as well as low-energy interaction models (e.g.
FLUKA or GHEISHA). This contribution will summarize the results of such
investigations. In particular, the validity of the new EPOS version 1.99 for
EAS with energy around 100 PeV will be discussed.
