连续梁边跨不设合龙段施工期间主梁临时托架结构计算分析

针对连续梁较为少见的“先合龙中跨后不设合龙段直接现浇边跨”的特殊合龙顺序,以埃塞俄比亚某在建连续梁为工程背景,介绍了自制托架施工边跨现浇段的工序及要点;通过建立有限元数值分析模型,结合现场温度与线形实测值,建立该地区短期简易温度场,对梁体结构所受温度效应进行分析,并对自制托架体系进行结构验算。结果表明:托架结构受力性能良好,通过自制托架实现边跨直接现浇是可行的;温度对梁体线形影响较大,在合龙前需将边跨梁端与托架临时锁定;对于类似合龙顺序的连续梁施工,该桥有一定借鉴意义。

Calculation and Analysis of Temporary Bracket Structure of Main Girder During Construction of Continuous Beam Side Span without Closing Section

In view of the rare closing sequence of"the segments of the side-span are casted without closure segments after the mid-span is closed"for the continuous beam,taking a continuous beam built in Ethiopia as the engineering background,the construction method and points of the side span cast-in-place segment with usage of self-made bracket system were introduced.Considering the field temperature and the measured elevation,a simple short-term temperature field in the area was established.The temperature effect of the beam structure and the mechanical property of the self-made bracket system were analyzed by establishing a finite element numerical analysis model.The results show that the bracket structure has a good mechanical performance,and it is feasible for direct cast-in-place with self-made brackets.The temperature has a great influence on the bridge alignment,and it is necessary to temporarily lock the end of side span and brackets before the closure construction.For other continuous beams with similar closing sequence,the bridge has certain reference value.