主跨245 m连续组合梁落梁技术研究

Research on beam falling technology of continuous composite beam with 245 m main span

以目前国内最大跨度的连续组合梁——主跨245 m的济南凤凰路北侧跨大堤引桥为研究背景,对边、中跨临时墩落梁高度敏感性进行分析,探讨了各临时墩不同步性落梁问题,提出了两种可行的落梁技术方案,即先中跨同步落梁后边跨落梁(方案一)与先边跨落梁后中跨同步落梁(方案二)。以临时墩起顶力小或起顶力大且落梁量大作为可操作性原则,对两种落梁技术方案的各临时墩起顶力、设备及落梁量等方面进行了对比分析。结果表明:落梁方案一具有边跨临时墩起顶力小,为630 t,落梁高度小,为5.7 cm,可操作性好的特点,而落梁方案二的边跨临时墩起顶力大,为3356 t,落梁高度为29 cm,可操作性差,最终采用方案一为最优的落梁技术方案,为类似的轻型连续组合梁桥工程的落梁作业提供参考。

Based on the research background of the approach bridge on the north side of Jinan Fenghuang Road with the main span of 245 m,which is the continuous composite beam with the largest span in China,we analyzed the high sensitivity of beam falling of temporary piers in side span and middle span,and discussed the problem of synchronous beam falling of temporary pier.Two feasible beam falling technical schemes were proposed,i.e.,first synchronous falling beam with middle span and then falling beam with side span(scheme 1)and first falling beam with side span and then synchronous falling beam with middle span(scheme 2).Taking the small jacking force or large lifting force and large beam falling amount of temporary pier as the operability principle,the jacking force,equipment and beam falling amount of each temporary pier of the two beam falling technical schemes were compared and analyzed.The results show that the scheme 1 has the characteristics of small jacking force of 630 t for side span temporary pier,small beam falling height of 5.7 cm and good implementation controllability,while the scheme 2 has large pier jacking force of 3356 t for side span temporary,beam falling height of 29 cm,and poor implementation controllability.Finally,the scheme 1 is adopted as the optimal beam falling technical scheme,which provides reference for the beam falling operation of similar light continuous composite beam bridge projects.