MUD BURST DISASTER-CAUSING STRUCTURE DURING CONSTRUCTION OF TUNNEL AND ITS CLASSIFICATION

Mud burst is widely concerned by tunnel engineering due to its universality, burying and severity. Seven mudburst disaster-causingstructures, including water and mud mixed filling karst, clay filled karst communicating with the earth surface, clay filling deep grike and bath, deep clay filled karst, fault mud or fault mylonite in main fault zone, uncemented rich water fault strong compression fracture zone, and clay with crushed rock block filling in bottom of karst, were advancedaccording to the relationship between water inrush and unfavorable geologic bodies. Three principles for classification and four types mud burst disaster-causingstructures(water and mud mixed filling karst, clay filled karst, filling clayand in fracture and gap between broken rock blocks, and fault mud or fault mylonite in main fault zone) also were advanced according to the composition of mudburst disaster-causingstructure, type of mud-resisting rock-soil plate and extensive engineering treatment measures in this paper.