Rockburst criterion and evaluation method for potential rockburst pit depth considering excavation damage effect  

作　　者：Jinhao Dai Fengqiang Gong Lei Xu 

机构地区：[1]Engineering Research Center of Safety and Protection of Explosion & Impact of Ministry of Education (ERCSPEIME),Southeast University,Nanjing,211189,China [2]School of Civil Engineering,Southeast University,Nanjing,211189,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第5期1649-1666,共18页岩石力学与岩土工程学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.42077244).

摘　　要：Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit depth.Taking two diversion tunnels of Jinping II hydropower station for example,the relationship between rockburst pit depth and excavation damage effect is first surveyed.The results indicate that the rockburst pit depth in tunnels with severe damage to rock masses is relatively large.Subsequently,the excavation-induced damage effect is characterized by disturbance factor D based on the Hoek-Brown criterion and wave velocity method.It is found that the EDZ could be further divided into a high-damage zone(HDZ)with D=1 and weak-damage zone(WDZ),and D decays from one to zero linearly.For this,a quantitative evaluation method for potential rockburst pit depth is established by presenting a three-element rockburst criterion considering rock strength,geostress and disturbance factor.The evaluation results obtained by this method match well with actual observations.In addition,the weakening of rock mass strength promotes the formation and expansion of potential rockburst pits.The potential rockburst pit depth is positively correlated with HDZ and WDZ depths,and the HDZ depth has a significant contribution to the potential rockburst pit depth.

关 键 词：Deep tunnel ROCKBURST Rockburst pit Excavation damage effect Hoek-Brown criterion 

分 类 号：TD353[矿业工程—矿井建设] TD325