超宽连续钢箱梁桥施工预拱度研究

Research on Pre-camber in Construction of Ultra-wide Continuous Steel Box Girder Bridge

摘要:

针对宽幅钢箱梁桥传统预拱度设计仅考虑纵向效应的不足，以实际工程为背景，明确横向预拱度的必要性，并揭示施工过程对预拱度计算结果的影响，完善宽幅桥梁预拱度计算方法。通过采用有限元仿真方法，充分考虑宽幅钢箱梁桥的实际施工流程建立施工阶段递进模型，同时建立一次成桥模型作为对比，通过对比计算结果开展分析。通过对施工阶段模型计算结果的分析，得到了宽幅钢箱梁桥精确的纵向施工预拱度、横向施工预拱度。对比结果显示，一次成桥模型与考虑施工过程的递进模型预拱度计算结果存在显著差异。宽幅钢箱梁桥预拱度设计需同时考虑纵向预拱度和横向预拱度，且施工阶段效应对预拱度计算的影响不可忽略，分析思路与结果可为同类工程的预拱度计算提供参考。

Abstract:

In view of the deficiency that the traditional pre-camber design of wide steel box girder bridges only considers the longitudinal effect, taking an actual project as the background, the necessity of the transverse pre-camber is clarified, and the influence of the construction process on the calculation results of pre-camber is revealed. The calculation method of pre-camber for wide bridges is perfected. Through the finite element simulation method, a progressive model of construction stages is established by fully considering the actual construction process of wide steel box girder bridges. At the same time, a one-time formed bridge model is established for comparison. Through the comparison of the calculation results, an analysis is conducted. By analyzing the calculation results of the model during the construction stage, the precise longitudinal construction pre-camber and transverse construction pre-camber of the wide steel box girder bridge are obtained. The comparison results show that there are significant differences in the pre-camber calculation results between the one-time bridge-forming model and the progressive model considering the construction process. The design of the pre-camber of wide steel box girder bridges needs to take into account both longitudinal pre-camber and transverse pre-camber, and the influence of the construction stage effect on the calculation of the pre-camber cannot be ignored. The analysis ideas and results can provide a reference for the pre-camber calculation of similar projects.