Initial Sinking Method for Large Open Caisson in a Highway Bridge Project
Initial Sinking Method for Large Open Caisson in a Highway Bridge Project
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DOI：
10.1007/978-3-319-97115-5_172
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Peng Li;Erxiang Song;Tianliang Zheng
中科院分区：
文献类型：
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作者：
Peng Li;Erxiang Song;Tianliang Zheng
沉井基础作为斜拉桥的锚基础，近年来得到了广泛的应用。大型沉井在施工过程控制和空间受力性能方面与中小型沉井有着不同的受力特点。一般情况下，大型沉井的排水下沉比不排水下沉的危险性更大。在沉箱下沉初期，由于叶片边缘没有浮力或侧向约束，叶片根部倾向于向外偏移，这可能导致沉箱结构底部的较大张力。因此，对于大型沉井，合理的首沉方案设计尤为重要。以某公路桥梁工程锚基础大型沉井为背景，建立了三维土-结构相互作用有限元模型，分析了沉井结构直径对初次下沉时内力的影响。计算结果表明，对于大型沉井，初始下沉方式对沉井结构产生的拉力有很大影响。文克尔地基上的结构模型在计算沉箱结构的变形规律和内力时可能会产生较大的误差。数值计算结果和结论可为类似大型沉井工程初沉方法的合理设计提供参考。
Open caisson foundation has been widely used as anchor foundation for cable-stayed bridge in recent years. Large scale open caisson displays different mechanical characters compared with small and medium-sized open caisson in both construction process control and spatial mechanical performance. Generally, the drainage sinking of a large open caisson is more dangerous than the non-drainage sinking. At the beginning of caisson subsidence, the blade foots tend to deviate outwards because there is no buoyancy force or lateral constraint at the blade edge, which may lead to larger tensional force at the bottom of the caisson structure. Therefore, proper design of the first sinking scheme is particularly important for large-scale open caisson. A three dimensional soil- structure interaction finite element modeling, which is based on a large-scale open caisson for anchor foundation of a highway bridge project, is carried out to analyze the influence of the caisson structure diameter on the internal force in condition of first sinking. Numerical results indicate for large-scale open caisson the initial sinking method has a great influence on the tensional force generated in the caisson structure. It is also revealed the model of structure on Winkler foundation may lead to significant error in calculating the deformation pattern and internal force of the caisson structure. The numerical results and conclusion will provide reference for properly design of initial sinking method of similar large-scale open caisson projects.