浮式拱围堰技术及其试验研究

Technology of floating arch cofferdam and its experiment research

浮式拱围堰施工技术,是在不放空水库的情况下将拱围堰先围住一部分坝面,创造"干作业"环境进行修补,施工完成后,将拱围堰空腔内的水排出,拱围堰自动升起漂浮在水中,用拖轮牵引到下一个施工单元,充水、下沉、就位、止水和抽干围堰内的积水,又创造出另一个"干作业"环境进行施工。针对满台城大坝冻融破坏最严重部位,建造一空心半圆钢筒围堰。实验结果表明,当两肢拱脚及围堰底部与大坝上游面之间的止水做完之后,抽出围堰内的积水,"干作业"环境形成,可以进行施工。

The construction technology of the floating arch cofferdam is first surrounding part of the damsurface without venting the reservoir,which can create the'dry job'environments to repair cracks on con-crete surface of dam. After completion of the construction, the water is discharged in the cavity of thearch cofferdam,and the arch cofferdam can automatically rise to float in the water. The floating arch coffer-dam is towed to the next construction unit by tugboat,and is water-filled,sank,placed,water sealed,drained the stagnant water inside the cofferdam to create another'DRY'environment for construction. Aim-ing to the most severely freezing-thaw damaged parts for Mai tai-cheng dam,a steel tube cofferdam ofsemi- round is constructed. When sealing is done,the water within the cofferdam is pulled out,and the'Dry work'environment is formed for construction.