大跨径混凝土钢管拱桥梁顶推施工技术研究

A Study on Launching Construction Technology of Long-Span Concrete-Filled Steel Tubular Arch Bridge

结合我国第一座高速铁路上承式钢管混凝土提篮拱桥“成(都)贵(州)高铁西溪河大桥”项目实际,对步履法顶推与拖拉法顶推施工技术进行比选,决定采用拖拉法顶推技术进行施工。将钢管拱圈偶数号桥墩立柱最底部拱圈用钢绞线进行串联,并对称预加拉力,减少了钢管拱上桥墩立柱水平位移;在钢管拱圈上对称斜拉钢绞线,对拱圈竖向位移进行有效限制,确保了顶推时钢管拱圈不发生变形。此外通过Midas/Civil空间有限元分析软件进行建模验算,分析受力状况,通过有效的质量控制与方法监测来确保施工方案顺利实施。实践证明,拖拉法顶推施工技术既经济又安全,保证了工程质量。

Combined with the situation of China’s first high-speed railway deck steel tube concrete basket arch bridge,Xixi River Bridge of Chengdu-Guiyang high-speed railway,the walking jacking construction technology is compared with the dragging jacking construction technology,and finally the dragging method is selected for jacking.In order to break through the bottleneck that some flexible pier columns on the steel pipe arch have weak stiffness and are easy to be damaged by external tension,the steel strands are connected in series in the arch ring at the bottom of the pier columns with even number of steel pipe arch rings.In addition,the horizontal displacement of pier columns on the steel pipe arch is minimized through symmetrical pre tension.In order to avoid serious deformation of the steel pipe arch ring due to bias,symmetrical cable-stayed steel strand is carried out on the steel pipe arch ring to effectively limit the vertical displacement of the arch ring and ensure that the steel pipe arch ring will not deform during jacking.Also,with the help of MIDAS / civil space finite element analysis software,the modeling and checking calculation is used to analyze the stress status,and the effective quality control and monitoring methods are used to ensure the smooth implementation of the construction scheme.The practice shows that the technology has proved economical and safe and can also ensure the project quality.