不同跨径高铁连续梁桥悬臂施工线形分析研究

Linear analysis research on cantilever construction of different spans continuous girder bridge for high-speed railway

结合高速铁路中主跨64,80和100 m的3种常见连续梁桥,基于Midas/civil软件平台,采用数值分析方法计算分析了悬臂施工过程不同工况下梁体的变形规律,并与施工过程中的实测值进行对比。研究结果表明:高速铁路连续梁桥刚度较大,活载引起的最大挠度较小,一般在5-15 mm范围;3种跨度连续梁桥的最大施工预拱度在20-30 mm范围,且方向向下;连续梁桥边跨合拢后,边跨向上变形,中跨向下变形;连续梁桥中跨合拢后,边跨向下变形,中跨向上变形;受混凝土收缩徐变的影响,连续梁桥的中跨出现微小的上挠,边跨受影响较小;施工过程中梁体变形实测值与理论值吻合较好,有限元结果能很好地反映梁体变形的实际情况。

According to three kinds of common continuous girder bridges with main span of 64, 80 and 100 m in high-speed railway, based on the software platform of Midas/civil, this article calculated and analyzed the de-formation variation of beam compared with actual measured values under different conditions during cantilever construction process. The results show that： The maximum deflection caused by live load is small, generally be-tween 5-15 mm, for stiffness of continuous girder bridges is much in high-speed railway. The maximum down-ward construction camber of three kinds of continuous girder bridges is between 20-30 mm. Side span is upward and midspan is downward after closure construction of side span, and side span is downward and midspan is up-ward after closure construction of midspan. Because of influence of shrinkage and creep of concrete, there is a ti-ny scratch for the midspan and is smaller for the side span. In the construction process, the deformation of the beam is in good agreement with the theoretical values and the results of the finite element method can reflect the actual situation of the deformation of the beam.