广昆铁路秀宁隧道不良地质段综合施工技术

秀宁隧道为双线大断面铁路隧道,全长13 187 m,是在建广昆铁路的控制性工程。隧址地段的工程和水文地质条件极为复杂,施工非常困难。主要不良地质有隧道出口滑坡、富水断层破碎带、富水岩溶、高地温、高地应力、放射性、煤层瓦斯及有害气体、软岩大变形、岩爆等。结合秀宁隧道隧址地层的地质条件,从隧道掘进、施工通风、安全生产等方面介绍秀宁隧道的主要施工方法和对策;另外对超前地质预报及工程难点与对策也作了说明。秀宁隧道的施工实践对类似地区长大隧道的施工有较好的参考价值。

Comprehensive Construction Technology for Poor Geological Sections of the Xiuning Tunnel on Guangtong-Kunming Railway Line

The Xiuning Tunnel is a double-line railway tunnel with large cross-section, and it has a length of 13 187 m. It is a controlling project and one of main projects of the Guangtong-Kunming railway now being built. The tunnel is located in a region with extremely complex engineering geological and hydrogeological conditions and enormous difficulties. Main poor geological conditions encountered include landside mass at the tunnel access, water-rich fault and crush zone, karst declog- ging, high geothermal area, high geo-stress area, radioactive zone, coal-bed gas and harmful gas, large deformation of soft rock, rock burst, etc. This paper introduces the major construction methods and countermeasures of the Xiuning Tunnel in- cluding tunnel excavation, construction ventilation, safety in construction and others aspects. Moreover, methods in tunnel geological forcasting, construction difficulties and countermeasures are also given in details. Construction practice of the Xi- uning Tunnel will contribute to the construction of other large tunnels in similar area.