Abstract: Superstructure stress concentration and cracking were often caused by the uneven foundation settlement during the design and construction of bridge across the estuary and in coastal area. ABAQUS was adopted to analyze the lateral displacement of the pile in the role of foundation settlement under six conditions, including the original design condition, the change the pile diameter, the increase of the anchor with various pile diameters, the increase of steel on the basis of cofferdam pile diameter as well as the change of the quantity and form of 0# cloth pile. In view of the pile foundation displacement under different conditions, the idea that the upper structure kept the bridge span unchanged was put forward, but the upper part was adjusted to the simply supported structure, and the hollow slab was used. The pile diameter of the lower part structure was still 1.2 m, and the soil on the pile pushing role was decreased through the setting of large diameter steel casing cofferdam. Treatment options were proposed, such as setting empty abutment, increasing tensile anchor structure, and the auxiliary measures of force dissipation hole. This method has achieved good results in practical application.

Key words: bridge engineering, bay bridge, foundation settlement, influence analysis, treatment method

摘要： 跨越河口及沿海海域的桥梁在施工及使用过程中，经常由于地基不均匀沉降，引起桥梁上部结构产生应力集中和开裂。采用ABAQUS分析了原设计工况，改变桩径，各桩径下增加锚索，桩径基础上增加钢围堰，改变0#台布桩数量、布桩形式6种工况下地基沉降作用中桩基的侧向位移情况。针对不同工况下桩基位移情况，提出上部结构保持桥梁跨径不变，但上部调整为简支结构，采用空心板。下部结构桩基直径仍采用1.2 m，并通过设置大直径钢护筒围堰减小土体对桩基的推挤作用，设置空箱桥台及增加锚拉结构，应力消散孔等辅助措施的处理方案。这套处理方法在实际运用中取得了良好的效果。

关键词: 桥梁工程, 跨海大桥, 地基沉降, 影响分析, 处理方案