秦淮河船闸扩容改造工程围堰设计方案优化

Cofferdam design optimization for modification work of Qinhuai River shiplock

秦淮河船闸扩容改造工程围堰地基具有强渗透性特点,故围堰必须具有较强的防渗能力,才能保证船闸主体进行干地施工。原围堰结构设计方案为:上游围堰采用土工织物袋双棱体结构;下游围堰迎水面采用双排钢板桩中间回填黏性土直立式结构,背水面采用回填黏性土斜坡式结构,经对"充填砂袋+防渗帷幕"、"黏土填筑+防渗帷幕+反压平台"及"黏土填筑+防渗帷幕+钢板桩"三种围堰结构设计方案进行比选优化,最终确定采用"黏土填筑+防渗帷幕+反压平台"的结构形式,保证了围堰结构安全和防洪进度,并取得了明显的经济效益。

Owing to the strong permeability of the cofferdam foundation in the expansion and modification project of the Qinhuai River shiplock, the cofferdam foundation must have a good anti-seepage capacity to ensure that the main body of the shiplock is under construction on a dry site. There were some problems in the original design proposals for the cofferdam structure, and hence it is necessary to further optimize the design schemes. After making the comparison and optimization of three kinds of the cofferdam structure design schemes：＂ filling sand bags ＋ impervious curtain, clay filling ＋ impervious curtain ＋ backpressure platforms and clay filling ＋ impervious curtain ＋ steel sheet pile＂, a final design scheme ＂clay filling ＋ impervious curtain ＋ backpressure platforms＂ has been adopted, thus ensuring the safety of the cofferdam structure and flood control progress, and having significant economic benefits. All of those may provide a useful reference for the design of the cofferdam structure with similar geological conditions.