Abstract: A new analytical model is developed to calculate the deformation of damaged rocking elements before rocking, which refers to an existing analogous spread plasticity model of rocking elements. With a new effective stiffness ratio accounting for the plastic deformation in calculation, a damage influence coefficient is proposed to consider the effects of damaged corners on the entire rocking elements. The analytical model is verified by the finite element model simulation and the results of existing experiments. The results indicate that the analytical model proposed in this paper could accurately predict the deformation of rocking elements before and after being damaged. The effective stiffness ratio related to the normal stress distribution at the contact surface is proved to be applicable in the analysis of rocking elements before rocking. By adjusting the damage influence coefficient, the effects of different damage degrees of corners on the stiffness of rocking elements can be explicated.