以闵浦三桥为例总结粉细砂层大直径钢管桩沉放工艺研究

Taking the Minpu Third Bridge as an Example to Summarize the Research on the Sinking Technology of Large-Diameter Steel Pipe Piles in Silty Fine Sand Layer

钢管桩以其承载力高、施工质量好等特点,在江河以及近海的桥梁基础中广泛采用。随着桥梁跨度上升,基础的深度不断加深,钢管桩的直径不断增大,钢管桩的沉桩施工难度也随之加大。针对大直径钢管桩在粉细砂层中沉放困难、沉放施工与航道保通相结合的情况,以上海市昆阳路越江大桥(后称闵浦三桥)的主塔桩基础施工工艺为例,通过采用合适的沉桩设备、合理的施工顺序,增大柴油锤型号、间隔复打等措施,将70 m钢管桩按照设计要求沉放到位,并经过检测验证桩基承载力,确保施工质量,为类似工程的大直径钢管桩的沉桩施工提供参考。

Steel pipe piles are widely used in river&offshore bridge foundations because of their high bearing capacity&good construction quality.With the rise of bridge span,the deepening of foundation depth and the increasing diameter of steel pipe pile,the difficulty of pile sinking construction of steel pipe pile also increases.In view of the difficulties in sinking large-diameter steel pipe piles in the silty fine sand layer and the combination of sinking construction and channel maintenance,taking the construction technology of the main tower pile foundation of Shanghai Kunyang Rd.Crossing-River Bridge(later known as Minpu Third Bridge)as an example,by adopting appropriate pile sinking equipment,reasonable construction sequence,increasing the model of diesel hammer,interval re-driving and other measures,the 70 m steel pipe piles are sunk in place according to the design requirements,and the bearing capacity of the pile foundation is verified through testing.The construction quality is ensured to provide reference for the pile sinking construction of large diameter steel pipe piles in similar projects.