积石峡水电站导流洞与中孔泄洪洞交叉段顶拱混凝土施工技术

Construction of the Crown Concrete of the Intersection Section of Diversion Tunnel and Middle Flood Discharging Tunnel in the Jishi Gorge Hydropower Station

积石峡水电站导流洞与中孔泄洪洞交叉段顶拱跨度大,断面为平顶扭面,支撑系统繁杂,顶拱混凝土浇筑模板支撑系统采用底部钢管支柱支撑桁架梁平台,平台上搭设碗扣脚手架支撑方法。此种施工方法的应用减少了对导流洞施工的干扰,加快了施工进度,保证了交叉段顶拱混凝土质量,确保了关键工期。

In the Jishi Gorge Hydropower station, the crown of the the intersection section of the diversion tunnel and flood discharging tunnel is of a large span and complicated support. The support of the moulding board for crown con- crete pouting use steel pipe post at bottom to support trusswork platform eupleck joint scaffold is build up. This con- struction technique reduces disturb to the diversion tunnel construction, speeds up the construction progress, ensure the good concrete quality and the key schedule of the project.