乌东德水电站左岸导流洞进口围堰拆除施工技术

Technlogy for inlet cofferdam demolition of diversion tunnel construction on left bank of Wudongde Hydropower Station

乌东德水电站左岸导流洞进口围堰采用预留岩埂及防渗墙作全年挡水围堰,进口围堰与导流隧洞进口建筑物距离最近只有2 m。按照建筑物安全的要求,围堰拆除不能影响其周边建筑物的使用功能,参建的四方单位对围堰岩埂及防渗墙爆破拆除施工方案参数选定、爆破安全防护进行了精细策划和讨论,制定了实施方案。经实践检验,实施方案充分可行,爆破技术和措施选择恰当,拆除效果可满足工程总体要求。

The reserved rock ridge and anti-seepage wall are adopted as the year-round water retaining cofferdam for the inlet cofferdam of the diversion tunnel on the left bank of Wudongde Hydropower Station,while the nearest distance between the inlet cofferdam and the inlet structures of the diversion tunnel is only 2m. In accordance with the relevant safety requirements on the structures,the working functions of the surrounding structures cannot be impacted by the demolition of the cofferdam,thus the selection of the parameters for the construction scheme of the blasting demolition of both the rock ridge of the cofferdam and the anti-seepage wall as well as the blasting safety protection are elaborately planned and discussed by the four participant units of the construction,and then the specific implementation scheme is made. The verification through practice shows that the scheme is fully feasible with the suitably selected blasting technology and measures and the demolition effect can meet the general requirement of the project.