论文部分内容阅读
岩爆是深埋工程建设面临的关键技术难题,岩爆风险的准确预测与评估至关重要。以全长超过16 km的锦屏二级7条不同洞径的深埋隧洞群岩爆实际发生情况作为统计依据,通过岩爆倾向性试验、应力状态、应力路径、蓄能深度、释放能量等多种方法和指标,对岩爆风险中存在的尺寸效应进行了深入探讨。研究结果表明,以小尺度岩石力学性质为基础的岩爆倾向性评价方法,由于难以反映地应力条件的变化,因此具有一定的局限性,而采用应力和能量分析方法则能够较准确地揭示岩爆风险中存在的尺寸效应。基于对深埋大理岩力学特性的深入认识,结合应力路径、蓄能能力、释放能量等因素的分析,7 m洞径的排水洞较6 m洞径的交通洞和13 m洞径的引水隧洞具有更高的岩爆风险,证明岩爆风险与隧洞尺寸并不存在完全的线性对应关系,存在一定的尺寸效应。根据现场实际统计数据,无论岩爆段所占比例,还是强烈~极强岩爆比例,排水洞也均高于交通洞和引水隧洞,而交通洞与引水隧洞的岩爆频次和强度基本相当,与理论分析结果基本吻合。
Rockburst is a key technical problem for deep-buried engineering construction. Accurate prediction and assessment of rockburst risk is of utmost importance. Based on the actual occurrence of rockburst in seven deep tunnel with more than 16 km in length, Jinping second-level secondary cavity is taken as the statistical basis. Through the rockburst propensity test, stress state, stress path, energy storage depth, energy release, etc. A variety of methods and indicators, in-depth study of the size effect of rock burst risk. The results show that rockburst tendency evaluation method based on small-scale rock mechanics has some limitations because it is difficult to reflect the change of the geostress conditions. However, the stress and energy analysis methods can reveal the rockburst more accurately The size effect in blast risk. Based on the deep understanding of mechanical characteristics of deep-buried marble and the analysis of factors such as stress path, storage capacity and energy release, drainage holes with 7-m diameter are compared with those with 6-m diameter and 13-m diameter diversion tunnel Which has a higher risk of rock burst. It is proved that the risk of rock burst does not have a completely linear relationship with the tunnel size, and there is a certain size effect. According to the actual field statistics, no matter the proportion of rock burst or strong ~ extremely strong rock burst ratio, the drainage holes are also higher than the traffic tunnels and diversion tunnels, while the rock burst frequency and intensity of traffic tunnels and diversion tunnels are basically the same, And the theoretical analysis of the basic agreement.