长大隧洞断层破碎带及蚀变岩层开挖支护技术的研究与应用

Research and Application of Excavation Support Technology for Long and Large Tunnels in Fault Fracture Zones and Altered Rock Formations

在硬梁包水电站引水隧洞掌子面掘进过程中,遇到了大小不等的断层破碎带及蚀变岩层,其稳定性差,若在施工中控制不当极易发生急剧变形、坍塌、涌水突泥等各种工程地质问题,安全风险极高,给工程的施工进度造成了极大影响。对硬梁包水电站引水隧洞掘进过程中穿过此类地层采取的减少对围岩的扰动、先行超前支护以增强围岩的整体性、开挖后及时采用钢支撑锚喷封闭、同时做好控制地下水等一系列措施进行了阐述,旨在为类似长大隧洞掘进过程中断层破碎带及蚀变岩层开挖支护施工提供参考。

During the excavation of the diversion tunnel of the Yingliangbao Hydropower Project,it encountered a fault fracture zones and altered rock formations of different sizes,where the stability was poor.If they were not properly controlled during construction,there would be various engineering geological problems such as rapid deformation,collapse,water gushing and mud bursting,which had a great impact on the construction progress of the project.In this article,a series of measures are described during the excavation process of that strata of the diversion tunnel of the Yingliangbao Hydropower Project,such as reducing the disturbance of the fence,first advance support to increase the integrity of the surrounding rocks,using steel support anchor spraying in time after excavation,and controlling groundwater at the same time,in order to provide reference for the construction of fault fracture zones and altered rock formations in the excavation of similar long and large tunnels.