北沿江公铁两用特大桥主塔基础设计研究  

Design of Main Tower Foundation of the North River Rail⁃cum⁃Road Bridge

作　　者：唐斌[1] TANG Bin(China Railway Major Bridge Reconnaissance&Design Institute Co.Ltd.,Wuhan 430050,China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,武汉430050

出　　处：《铁道建筑》2021年第6期33-35,48,共4页Railway Engineering

摘　　要：北沿江公铁两用特大桥是国内外首次采用最大跨度无砟轨道结构的斜拉桥,主桥跨度布置为(111.4+172+400+197+111.4)m。桥址地质结构复杂,基础结构设计难度大。采用有限元法建立桥梁基础模型,对圆端形沉井基础和钻孔桩基础进行方案比选,确定桥梁深水基础形式,并分析主塔基础静力特性。研究结果表明:采用圆端形沉井基础沉井施工难度大且造价偏高;推荐采用受力性能好、造价低、施工周期短且工艺成熟的直径为2.5 m整体群桩基础方案,按摩擦桩设计,桩长130 m。桩基础方案有效减小了桥塔基础规模,控制了基础沉降,节约了施工工期,并满足受力要求。The North River Rail⁃cum⁃Road Bridge is the first cable-stayed bridge with the largest span ballastless track structure at domestic and abroad.The main bridge span is(111.4+172+400+197+111.4)m.The geological condition of the bridge site is complex,and the design of the foundation structure is difficult.The finite element method was used to establish the bridge foundation model.The round-end-shaped caisson foundation and the bored pile foundation were compared and the deep-water foundation form of the bridge was determined.The static characteristics of the main tower foundation was analyzed.The research results show that the construction of a caisson with a round-end-shaped caisson is difficult and the cost is higher.By comparison,aϕ2.5 m integrated pile group foundation is recommended due to its good mechanical performance,low cost,short construction period and mature technology.According to the design of friction piles,the pile length is 130 m.The pile foundation scheme effectively reduces the scale of the bridge foundation,controls the settlement of the foundation,saves the construction period,and meets the stress requirements of corresponding codes.

关 键 词：斜拉桥 桥塔基础 沉井 钻孔桩 方案比选 结构设计 桥梁设计 

分 类 号：U448.121[建筑科学—桥梁与隧道工程]