深埋硬岩隧洞岩爆倾向性指标RVI的建立及验证

DEVELOPMENT AND VALIDATION OF ROCKBURST VULNERABILITY INDEX(RVI) IN DEEP HARD ROCK TUNNELS

在总结国内外岩爆倾向性研究的主要成果和理论方法的基础上,针对性地提出适合于深埋隧洞工程的岩爆倾向性评估新方法的建立过程和基本构架。分析锦屏II级水电站深埋隧洞群中62例岩爆案例,揭示岩爆的特征和主要控制因素,在此基础上提出新的岩爆倾向性指标RVI及其建立方法,确定RVI中岩爆控制因素的选取原则。RVI由4个控制因子构成,即应力控制因子Fs、岩石物性因子Fr、岩体系统刚度因子Fm和地质构造因子Fg,4个控制因子分别反映不同岩爆控制因素对岩爆倾向性的贡献。研究发现,锦屏II级水电站深埋隧洞岩爆破坏深度与RVI存在显著的相关性,建立的经验关系式的确定系数可达到80%以上,该经验关系式可评估深埋隧洞工程的岩爆倾向性和破坏程度。锦屏II级水电站深埋隧洞典型岩爆实例分析验证RVI的适用性。

Based on summarizing the main results and theoretical methods of rockburst vulnerability evaluation,the development process and basic framework of a new rockburst vulnerability evaluation method for deep tunnels are put forward.The 62 rockburst cases which occurred in deep tunnels of Jinping II hydropower station are analyzed;and the characteristics and main controlling factors of rockburst are revealed.New empirical assessing index—rockburst vulnerability index（RVI） and its established methods are both proposed;while the principle of selecting controlling factors is confirmed.RVI is constituted by four controlling factors,namely stress control factor Fs,rock petrophysical factor Fr,rockmass system stiffness factor Fm and geologic structure factor Fg,which respectively reflect different contributions of rockburst controlling factors to rockburst vulnerability.It is found that there is a significant correlation between the failure depth of rockburst and RVI.An empirical equation is established and its determination coefficient is more than 80%.The empirical equation can be used for evaluating the rockburt vulnerability and its damage level.The applicability of RVI method is verified through the analysis of representative rockburst cases which occurred in deep tunnels of Jinping II hydropower station.