PRESENT SITUATION OF ROCK EXCAVATION DAMAGED ZONE IN UNDERGROUND ENGINEERING

The excavation of underground engineering will inevitably form the damage zone in the surrounding rock mass. It is of great importance to understand the distribution and evolution of the damage zone for the stability and safe operation of the project. This paper reviews the research course of excavation damage zone from the concept, experiment, theory,hot topic and engineering applications and summarizes the results of predecessors' work. on the basis of this I thought:(1)The excavation damage zone will continue to be one of the hot issues in the future. To form a unified quantitative definition helps to research. (2)Under complex conditions, it is still impossible to judge the range and distribution of excavation damage zone by theory, and the existing prediction methods of excavation damage zone need to be improved constantly. (3)The formation and evolution mechanism of excavation damage zone under coupling conditions and the excavation response under real boundary conditions still need to be studied. (4)The influence of the evolution process of the damage zone on the mechanical parameters of rock mass is not clear, and multi-scale and multi-level studies can be carried out by means of numerical simulation. (5)It is necessary to strengthen the research on the deep excavation damage zone and the aging deformation effect.