Abstract: Rock salt has been recognized as a highly suitable medium for geological storage of oil, gas and radioactive wastes because of its low-permeability, high-ductility, low-creep strength and capacity for self-healing. The self-healing of damage, as a significant part of damage evolution of rock salt, has important influence on the stability and permeability of rock salt in excavation disturbed zone (EDZ). The research progress of damage self-healing property of rock salt is summarized from the aspects of mechanism, influencing factors and constitutive models, and the research advances in damage self-healing property of rock salt in China are summarized. In the EDZ, damage healing can occur under three different mechanisms: mechanical closure, diffusive healing driven by surface energy reduction and healing by recrystallization. The major factors that may affect crack healing are stress, temperature, initial damage, humidity, chemical environment and so on. The MDCF model and the Lux/Hou model which consider the self-healing characteristics of salt rock damage are introduced. Furthermore, several key research directions on the damage self-healing of layered salt rock in China are put forward.

Key words: rock salt, crack healing, damage evolution, utilization of salt caverns, constitutive model