溪洛渡水电站泄洪洞进口渐变段衬砌混凝土施工技术

Concrete Construction for Entrance Transition Lining of Spillway Tunnel at Xiluodu Hydropower Station

异型渐变结构在水工隧洞进出口建筑物中较为常见,其断面多由矩形断面与圆形断面相互过渡,是一种易见却又难以施工的洞段,其结构型式复杂、过流面混凝土成型质量要求高,而混凝土衬砌不具备采用钢模台车进行浇筑的条件,因此,混凝土衬砌模板的设计、运输、定位、加固困难,而且模板面板平整度、刚度及模板支撑体系对混凝土体型、平整度均有较大的影响。结合溪洛渡水电站右岸泄洪洞进口渐变段混凝土衬砌分段分层、施工方法、施工程序以及模板制作情况等多工序进行阐述,可为今后同类工程施工提供一定的经验和借鉴。

Special-shaped structures are especially common in intake and outlet structures of hydraulic tunnels. The tunnel section is gradually changed from rectangle into circular,resulting in difficult construction,complicated structural forms,high quality requirements for concrete forming in wetted cross section. In addition,steel form jumbo is unsuitable to be used in concrete lining construction. Therefore,it is difficult to carry out concrete lining form design,transportation,location and reinforcement. Influence of form face flatness,stiffness and supporting system on concrete configurations and flatness is significant. In this paper,concrete lining in sections and in layers are carried out in intake transition section of right bank spillway tunnel at Xiluodu hydropower station. Construction methods,construction procedures and form works are described to provide experiences and references to the similar projects in the future.