二滩水电站导流隧洞围岩锚杆支护实践研究

Surrounding rock supporting of diversion tunnel of Ertan Project

二滩水电站的施工为国际招标施工。根据挪威咨询专家组（ＡＧＮ）建议，导流洞围岩喷锚支护参数根据现场岩体开挖后具体情况确定，即在现场直接确定锚杆位置、长度及喷混凝土层厚度。在导流洞各阶段施工开挖过程中，在ＡＧＮ专家组指导下，我们在现场直接参与了此项工作的实施。本文对围岩锚杆实际支护情况进行了初步的总结和分析，将实际支护统计结果与锚杆布置设计参数及由Ｑ系统分类建议参数进行了比较，并对在岩体开挖现场布置锚杆的实施方式进行了讨论。

The international tender way was adopted for the construction of Ertan Hydropower Station. According to the recommendations of specialist group of Norway(SGN),the parameters of shotcrete and anchor support, namely positions and lengths of anchor bars and thickness of shotcrete, must be determined in terms of actual rockmass conditions after excavation. During the whole process of excavating the diversion tunnel, under the guidance of SGN,author directly took part in the implementation of this work in the field. In this paper, preliminary summing-up was carried out on the implementation of anchor bar support,and preliminary analysis on stressed states of anchor bars. Comparisons between the statistical results of actual support conditions and the design parameters of arrangement of anchor bars and recommended parameters in Q classifying system were made. And the implementation ways for installing anchor bars in the excavation field were discussed.