先简支后连续桥梁体系转换阶段挠度计算研究

The study on calculation of deflection of system transformation stage with simply-supported continuous concrete

在先简支后连续桥梁施工过程中,控制梁体在正弯矩区预应力和墩顶负弯矩区预应力作用下的上拱变形是确保桥梁线形和防治开裂的关键步骤。本文通过理论推导了先简支后连续桥梁体系转换阶段挠度计算公式,并结合某高速公路四跨一联的40m先简支后连续小箱梁桥实桥跟踪测试对比分析结果,证明该公式可以满足先简支后连续桥梁线形控制要求,可为同类桥梁提供参考。

During the construction of simply supported continuous bridge, the key step to ensure the alignment of the bridge and prevent the cracking is to control the upwarp of the beam under the action of the positive moment zone and the negative moment zone at the top of the pier. In this paper, the deflection formulas for the transition phase of the simply supported continuous bridge system are deduced by theory, combining with the comparation and the analysis results of a 40 m simply supported continuous small box girder bridge with four spans, it is proved that the formulas can meet the requirements of the alignment control of the simply supported continuous bridge and provide reference for similar bridges.