Characteristics and Prevention of Rockburst Damage in High Stress Brittle Hard Rock Underground Powerhouses

The measured maximum principal stress on the left bank of Shuangjiangkou Hydropower Station is 37.82 MPa, which is the highest measured in-situ stress of the underground powerhouse system of domestic hydropower stations under construction and already under construction, belonging to a high to extremely high stress area. Based on a large number of investigations, statistics, and summary of the macroscopic development characteristics of rockburst damage in underground caverns of large hydropower projects in the west, a new concept of "shallow cake layer type", "fan shaped plate crack uplift type", "large plate crack sliding type", and "new cracks" high stress brittle hard rock failure characteristics is proposed, and a geomechanical model of deformation and failure of surrounding rock of high stress brittle rock mass is proposed. Based on this, the prevention and control methods of ultra high stress rockburst disasters and support measures for brittle hard rock lag rockbursts during the technical construction stage are proposed. It has certain guiding significance for the prediction and prevention of rockburst, design and construction of similar hydropower projects, Sichuan-Tibet Railway, and other projects.