积石峡导流洞交叉段顶拱模板及支撑系统设计与应用

Design and Application of Moulding Board and Support of the Intersection Section Crown of the Diversion Tunnel in the Jishi Gorge Hydropower Plant

积石峡水电站导流洞及中孔泄洪洞工程交叉段顶拱形式为导流洞和中孔泄洪洞2个城门型顶拱相切形成的,跨度大、衬砌后净高大、衬砌厚度大。针对以上情况,混凝土施工中底部采用钢管立柱,钢管顶部依次采用标准桁架、WD J多功能碗扣架、模板排架作支撑,确保了22.34 m大跨度隧洞平顶扭面拱混凝土衬砌的安全施工及导流洞与中孔泄洪洞标准段的顺利施工,为大跨度平顶结构隧洞的施工积累了经验。

In the Jishi Gorge Hydropewer station, the Crown of the intersection section of the diversion tunnel and flood discharging tunnel is the result of tangency of the gate-type crowns of the diversion tunnel and flood discharging tunnel, and is of large span, large net hight after lining and large lining thickness. In accord with these conditions, construction techniques, such as use of steel pipe post at bottom, use of standard trusswork and use of mul ＂tffunctional WDJ cuplock joint scaffold and frame bent as support, are applied in construction to ensure the safe constriction of concrete lining of the pinch plane arch of the fiat tunnel of 22.34m span and smooth construction of the standard sec- tions of the flood discharging tunnel and diversion tunnnel, and the constuction with application of those measurement also accumulates experiencies for the construction of large span tunnel of flattop structure.