  In this paper, we apply Borcea--Voisin's construction and give new examples
of Calabi--Yau fourfolds $Y$, which admit an elliptic fibration onto a smooth
threefold $V$, whose singular fibers of type $I_5$ lie above a del Pezzo
surface $dP \subset V$. These are relevant models for F-theory according to
papers by C. Beasley, J. J. Heckman, C. Vafa. Moreover, at the end of the paper
we will give the explicit equations of some of these Calabi--Yau fourfolds and
their fibrations.
