摘要
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。
Rock burst is a key problem in the engineering construction. An accurate forecast and assessment of rock burst risk is crucial. The actual rock burst occurred in the deep buried tunnel group of Jinping II with 7 tunnels of different diameters and total length more than 16 km. The rock burst tendency test was carried out and the stress condition,stress path,energy storage depth and releasing energy were investigated. The test of rock burst tendency is based on the mechanical properties of rock in small scale,which is difficult to reflect the influence of geostress on rock burst risk,so the method has some limitations. Accordingly,the stress and the energy analysis method are able to reveal accurately the problems of size effect. The results based on the mechanical characteristics,the stress path,the energy storage capacity and the energy releasing analysis of deep buried marble show that the drainage tunnel of 7 m diameter has a higher risk of rock burst than the traffic tunnel of 6 m diameter and the diversion tunnel of 13 m diameter. This proves that there is no linear relation between the rock burst and size. According to the actual statistical data,the ratio of rock burst and the proportion of strong to super strong rock burst of the drainage tunnel are also higher than those of the traffic and diversion tunnels. The frequency and intensity of rock burst of the traffic tunnel and diversion tunnel are in the same level,and the result is consistent with the theoretical analysis.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第10期2514-2521,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金青年基金资助项目(51409265)
中国电建集团公司科技项目(GW–KJ–2013–11)~~
关键词
隧道工程
深埋隧洞
岩爆风险
尺寸效应
锦屏二级
大理岩
tunnelling engineering
deep buriedtunnel
rock burstrisk
size effect
Jinping Ⅱ
marble
