Abstract: The decision of the form of rockmass engineering instability has been an important issue in the rock engineering field.Based on the summary of the previous studies, the energy dissipation principle and the catastrophe theory, the criteria for the plastic energy catastrophe of rockmass engineering instability were proposed and applied in judging the stability of the horizontal ore stratum in Jinchuan No.2 Mine.Based on  the site engineering geological survey and acoustic detection of the horizontal ore stratum, it is concluded that the ore stratum was newly destroyed and is in the post-peak region, and no abrupt collapse will occur in its mining process.  

Key words: Rockmass engineering, Plastic energy catastrophe, Horizontal ore stratum, Geological survey, Catastrophe instability