Micro–macro modeling of brittle creep and progressive failure subjected to compressive loading in rock

A major challenge of rock mechanics is to link the time-dependent crack growth with macroscopic mechanical behavior. A new micro–macro method is presented to model the brittle creep and progressive failure of rock in compression. The Ashby’s microcrack model, Charles’ crack growth law and a new theoretical relation are incorporated into this method. This new relation is suggested to establish the linkage between microcrack growth and macroscopic strain based on the macroscopic and micromechanical definition of rock damage in this paper. The long-term strength of rock could also be calculated using this suggested micro–macro method. Rationality of the suggested method is verified through the theoretical and experimental results. Furthermore, effects of confining pressure on brittle creep and progressive failure of Sanxia granite is investigated. Theoretical corresponding relation between crack growth, damage and strain is investigated. And theoretical foundation of deep-buried construction design is also discussed in this paper.