台州湾跨海大桥通航孔桥悬拼匹配关键问题研究

Research on Key Problems of Matching Technology in Cantilever Erection of Navigation Opening Bridge of Taizhou Bay Cross-Sea Bridge

台州湾跨海大桥通航孔桥为主跨488m的双塔双索面组合梁斜拉桥,在主梁悬臂拼装过程中,采用"焊接边腹板—提前挂索—吊机卸载"技术完成梁段匹配连接。为了确定该技术的合理吊机卸载比及提前挂索的合理预张力,采用Abaqus建立部分悬拼梁段的有限元模型,研究匹配截面的变形规律及吊机卸载比对不匹配变形值的影响,分析提前挂索的索力对边腹板焊缝和斜拉索锚固区桥面板受力的影响,并采用曲线拟合的方法给出提前挂索的合理预张力计算公式。结果表明:吊机的合理卸载比为37%,提前挂索的合理预张力与一张索力的比值为60%～74%。

The Navigation Opening Bridge of the Taizhou Bay Cross-Sea Bridge is a cable-stayed bridge that has a structure of double-pylon double-cable plane composite girder with a main span of 488 m.During the process of cantilever erection of the main girder,the technique of"side web welding,cable pre-installation,crane unloading"was employed to match and connect the girder segments.To determine the reasonable unloading ratio of the cranes and reasonable pretension of pre-installed cables,we established a finite element model of several cantilever segments by the Abaqus.Meanwhile,we studied the deformation law of matching section and the influence of unloading ratio on mismatched deformation,and analyzed the influences of cable force of pre-installed cables on stress of side-web welding and the deck of the anchorage zone.Moreover,we proposed an appropriate pretension formula for pre-installed cables by using the curve fitting method.The results indicate that reasonable unloading ratio of bridge deck cranes is 37%,and the reasonable ratio of pretension to the first pretension of cable is 60%-74%.