In this paper distinct element method is developed for the collapse analysis of sea ice ridge. Rotation of the rigid body is described using quarternion to prevent the accumulation of numerical error, and interactions between rigid bodies are expressed using impulsive forces. Fusions between elements are expressed by the springs eletween centers of masses. The ridge is assumed to be the assemble of rectangular body, and by falling the bricks on the cover the ice model was generated. The analysis of the collision of the ridge model with offshore structure is analyzed and compared with the experimental data, as well as several empirical formulae.