急流中的钢围堰下沉及环封施工技术

主要介绍了利用六七式铁路舟桥、六四式铁路军用梁等器材拼组成水上浮龙门吊，在流速较大、河床为松散卵石覆盖的情况下，浮运、起升、下沉钢围堰以及锚固方法。由于松散卵石覆盖层底部是承台基底，为了减少水下爆破施工工序，提高工效，鉴于基底岩石的整体性而采用了钢围堰环封施工技术，解决了水中承台及墩身施工难题，为今后类似工况下的施工提供了借鉴。

The Sinking and Ring-Sealing Construction Techniques for Large Steel Cofferdams in Swift Current

Introduced in the paper are using type-67 railway pontoon bridges, type-64 military railway beams and other equipments and materials to assemble floating gantry cranes in water,which are to be used at sites in rivers,the riverbed of which is loose-cobble-covered and the current of which is very swift,for float-transporting, lifting and sinking steel cofferdams, and the anchoring methods. Owing to the fact that the loose-cobble-covered riverbed will be used as the cap base, and taking into account the integrity of the bottom rock, the steel-cofferdam-ring-sealing technique is adopted so as to reduce the construction procedures of the underwater blasting operation and improve construction efficiency. The adoption of the new construction techniques helps solve the difficult problems of building underwater pile caps and pier bodies. The paper may serve as a useful reference for the construction of other projects under similar construction circumstances in the future.