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The construction of second stage cofferdam with a height of 80 m in waterdepth 60 m is one of keyXtechnology problems of TGP. A new keytechnology tackling topic about deepwater cofferdam was started in 1979 in combination with the desigh and construction of upstream cofferdam of main channel of Gezhouba Project, where instead of traditional inclined blunket scheme, a vertical impervious cutoff wall inside the cofferdam scheme had been successfully used under water depth 20 m. Primary technology problems... The construction of second stage cofferdam with a height of 80 m in waterdepth 60 m is one of keyXtechnology problems of TGP. A new keytechnology tackling topic about deepwater cofferdam was started in 1979 in combination with the desigh and construction of upstream cofferdam of main channel of Gezhouba Project, where instead of traditional inclined blunket scheme, a vertical impervious cutoff wall inside the cofferdam scheme had been successfully used under water depth 20 m. Primary technology problems were detailedly resolved through the National Keytechnology R&D Program of China during"Seventh and Eighth FiveYear Plan Periods". The study results were adopted in TGP design. The smooth construction and safe operation over 4 years proved that the recommended scheme and main technology measures are successful. 三峡工程二期深水围堰水深60m,堰高80m,是三峡工程重大技术问题之一,用传统的斜墙铺盖方案不可靠,为此,1979年开始结合葛洲坝大江上游围堰设计施工中的成功经验进行科技攻关。三峡围堰方案将葛洲坝围堰所采用的堰体防渗墙方案作为攻关的主攻方向。经"七五"、"八五"攻关解决了主要的技术问题,其成果用于设计和施工。施工及运行结果证明,攻关提出方案和主要技术措施是成功的。 In light of the main span construction of the large bridge over Beidu Fenghua River of west part of Ningbo Loop Expressway, this paper introduces the construction technology of the pile supported foundation cofferdam effected by tide in deep water. Comparing three construction schemes of pile cap cofferdam, it mainly introduces the execution, attentions, outcome of the single-double wall composite steel cofferdam scheme, and gives reference for other similar projects. 结合宁波绕城高速公路西段北渡奉化江特大桥主桥水中承台施工实例,介绍受潮汐影响的江中低桩承台深水桩基础围堰施工技术。通过对3种承台围堰施工方案的利弊比较,重点介绍了单一双壁组合钢围堰实施情况和注意事项,为其它类似工程施工提供借鉴。
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