Abstract: Most fields of geotechnical engineering are related to the unloading process of rock and soil. It is of great theoretical and practical significance to study the mechanical properties of cracked rockmass under unloading. Based on the theory of linear elastic fracture mechanics, a generalized model for cracked rockmass was established, The research results show that fractured rockmass is unloaded along different routes, the stress intensity factor is different from the mechanical properties exhibited, and the unloading of fractured rock along the least main stress has only the property of certain stage of the unloading along the greatest main stress.

Key words: Cracked rockmass, Unloading, Stress intensity factor, Deformation property