Abstract: The concept of disintegration and disintegrated rock mass is put forward in accordance with the practice of geotechnical engineering, geotechnical mechanics, rock mechanics and civil engineering. The failure modes and lost-stabilization types for disintegrated rock mass are discussed. According to thermodynamic principles and from the viewpoint of microscopic struc-
ture, the process of rock disintegration is virtually a kind of internal energy dissipation, and the realization of disintegration means that a partial energy is dissipated to produce new cracks.The steady criterion for disintegrated rock mass is proposed.

Key words: disintegration, failure mode, rock mechanics, thermodynamic analysis, criterion, hole damage