锦屏二级水电站引水隧洞岩爆洞段开挖技术措施

Engineering Measures in Excavation of Rock Burst Sections of Headrace Tunnels at Jinping Ⅱ Hydropower Station

大埋深、高地应力区地下工程施工普遍会遇到岩爆问题。如何预防和防止岩爆对施工人员造成伤害、对工程造成破坏是大埋深、高应力地区地下工程施工中的难点,一直没有成熟可靠的施工措施避免岩爆造成的危害。锦屏二级水电站引水隧洞群埋深普遍达1 500~2 520 m,地应力达到70 MPa,岩爆发生频繁。通过工程参建单位和科研机构的共同努力,采取了“主动预防、被动治理相结合”的方式,总体顺利完成了引水隧洞的开挖贯通,其施工技术措施和经验可供类似工程参考。

Underground project construction in large embedded depth and high in- situ stress area ordinarily will face rock burst problem. How to prevent rock burst hurt to builders and damage to project is a challenge. At Jinping Ⅱ hydropower project,embedded depths of headrace tunnels are generally 1500 m to 2520 m and in- situ stress up to 70 MPa,resulting in frequent rock bursts. With joint efforts of participated units and scientific research institutions,by taking measures of 'positive prevention combined with passive treatment',excavation of headrace tunnels were completed successfully. The construction engineering measures and experiences are provided to similar projects.