  The effects of biaxial tensile strain on the structure, electronic states,
and mechanical properties of silicene are studied by ab-initio calculations.
Our results show that up to 5% strain the Dirac cone remains essentially at the
Fermi level, while higher strain induces hole doping because of weakening of
the Si$-$Si bonds. We demonstrate that the silicene lattice is stable up to 17%
strain. It is noted that the buckling first decreases with the strain (up to
10%) and then increases again, which is accompanied by a band gap variation. We
also calculate the Gr\"uneisen parameter and demonstrate a strain dependence
similar to that of graphene.
