The paper describes numerical and analytical studies on load bearing capacity and stress distributions in/along rockbolts during pull-out tests considering elastic and inelastic behaviours of interfaces. Numerical studies are carried out by a FE method, and closed form solutions are presented assuming an elastic-softening-plastic flow behaviour of bolt-grout interface. Parametric studies on stress distributions in/along rockbolts subjected to pull-out forces, assuming elastic behaviour of the material system are made. Two hypothetical pull-out tests of rockbolts, of which interfaces exhibit inelastic behaviour, are analysed and results are presented and discussed with other works already reported in literature.