摘要
阆中嘉陵江四桥为独塔双索面斜拉桥,采用群桩接承台基础,针对基础施工难点进行施工方案设计,确定桩基采用在水上作业平台上布置钻机冲孔施工,承台利用双壁钢围堰进行浇筑,有限元计算结果表明各构件刚度、强度和稳定性均满足要求。施工时,沿墩位布置施工栈桥,栈桥基础钢管桩采用履带吊配合振动桩锤插打,上部结构利用履带吊进行安装。水上作业平台布置于主墩墩位,平台台面与栈桥桥面顺接,在完成基础成桩作业后用于钢围堰下放与安装。钢围堰分段进行拼装,逐节下放后接长形成整体,经检查合格后采用整体斜面推进法浇筑封底混凝土,在封底混凝土强度达到设计要求并经抽水检查封水成功后,按分段定点、薄层浇筑、循序推进的原则分2次浇筑承台。
The Fourth Jialingjiang River Bridge in Langzhong is a single pylon cable-stayed bridge with double cable planes . The bridge foundations are composed of group piles plus pile caps .In light of the complexities of fundation construction ,the construction scheme was designed . The piles were constructed using the drills placed on the operation platform above the river to do hole drilling .The pile cap was cast using the double-wall steel cofferdam .The results of the finite element calculation indicated that the stiffness ,strength and stability of each component could meet the requirements .During the construction ,the construction trestles were built along the pier position and the steel pipe piles of the trestle foundation were driven by the vibration pile hammer with the support of the crawler crane .The superstructure of the bridge was erected by the crawler crane .The operation platform above the river was placed at the sites of the main piers ,the surface of the platform was extended to connect with the deck of the trestle ,which would be used for the steel cofferdam lowering and erection after the completion of the pile construction .The steel cof-ferdam was assembled section by section to be lifts ,which were in turn lowered into position one by one and lengthened to be a whole .When the steel cofferdam was identified to be qualified ,the casting of the bottom sealing concrete proceeded on an overall oblique surface .After the strength of the bottom sealing concrete reached the design requirements and the water sealing operation was proved perfect by the water-pumping test ,the pile cap was cast by two times following the princi -ple of sectional positioning ,thin-layered casting and step-by-step proceeding .
出处
《世界桥梁》
北大核心
2014年第2期52-56,共5页
World Bridges
关键词
斜拉桥
水中基础
施工栈桥
水上作业平台
钢围堰
桥梁施工
有限元法
cable-stayed bridge
in-water foundation
construction trestle
operation platform above river
steel cofferdam
bridge construction
finite element method
