桥梁沉井基础抗震性能研究现状及展望

Research status and prospect on seismic behavior of bridge caisson foundation

随着国内外大跨桥梁特别是跨海桥梁建设的迅速发展,沉井基础在桥梁基础中所占的比例越来越大。虽然沉井基础作为1种刚性基础具有良好的力学性能,然而震害实践表明沉井基础在地震作用下也并非万无一失。通过分析国内外典型桥梁沉井基础的震害特征发现,沉井基础的地震破坏与桩基础有显著差异,且与埋置深度有直接关系;研究表明:地震作用下沉井基础的破坏机理及地基承载力与静力作用下明显不同,但目前在该方面的研究还较为欠缺;总结和对比了现有几种沉井基础-土相互作用研究方法,并分析了几种研究方法的优缺点和适用场合;同时也归纳和对比了各国抗震规范对桥梁沉井基础的基本规定、适用范围、计算方法和构造规定等方面的内容。最后结合现有的研究现状对沉井基础抗震性能研究的发展方向进行了展望,此外,随着我国跨海、跨江及跨库区大跨桥梁建设的发展,地震力和波浪力等多灾害因素共同作用下深水沉井基础桥梁破坏机理及设计方法的研究势在必行。

By analyzing the seismic damage characteristics of typical bridge caisson foundation at home and abroad,the significant difference between caisson foundation and pile foundation wre found,which is directly related to the buried depth.The research shows that the damage mechanism and bearing capacity of caisson foundation under earthquake action are obviously different from that under static action,the research.Several existing methods caisson base-soil interaction were summarized and compared,and their advantages,disadvantages and applications were analyzed.The basic provisions,application scope,calculation method and construction provisions of seismic codes for bridge caisson foundation were summarized and compared.Finally,the development direction of research on seismic performance of caisson foundation was prospected.In addition,with the development of cross-sea,cross-river and cross-reservoir bridge construction in China,it is imperative to study the damage mechanism and design method of deep-water caisson foundation bridge under the action of multiple disaster factors such as seismic force and wave force.