中文摘要：

钢板桩围堰合理的内支撑施工方案对施工安全、工期长短、成本大小均有一定的影响。以阜阳至六安铁路颍河特大桥深水基础超长钢板桩围堰施工实践为例,通过建立钢板桩、内支撑和土层相互作用的三维整体有限元模型,根据封底混凝土施工时机的不同,选择4种施工方案,对超长钢板桩围堰内支撑施工方案进行了探讨。结果表明：封底混凝土施工越早,对围堰结构的整体安全越有利;实际采用的施工方案要根据桥址处工程地质条件,结合实际工程情况,经方案比选和分析论证以后确定。

英文摘要：

Reasonable construction scheme of internal bracing for steel sheet pile cofferdam affects construction safety and construction period and construction cost.A case study was done for super-long steel sheet pile cofferdam construction of deepwater foundation at Ying River Bridge of railway line from Fuyang to Lu＇an.Three-dimensional finite element model considering steel sheet pile and internal bracing and soil layer is established.Four construction schemes are selected according to different construction opportunity of bottoming concrete.Construction scheme of internal bracing is discussed for steel sheet pile cofferdam.Results show that earlier construction time of bottoming concrete may provide safer cofferdam structure,and the actual construction scheme should be determined by scheme comparison and analysis according to engineering geological conditions of bridge site and actual engineering situations.