【作者】 李新华；

【导师】 李亚东；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 顶推法施工越来越多地应用于钢箱梁桥的架设之中,但是目前钢箱梁顶推法施工中存在着诸多尚待解决的问题。本文以宁波市福明桥为工程背景,对钢箱梁斜拉桥顶推过程中的部分关键问题进行研究,以期为今后同类桥梁的设计和施工提供参考。本文首先介绍了顶推施工工艺,分析了顶推施工中钢箱梁产生累积制造误差的原因,并给出了制造误差引起的主梁次内力的计算方法。在此基础上,以减小累积制造误差为目的,对临时墩的位置进行了优化,得到了满足主梁累积制造误差最小的临时墩位置。然后,通过建立顶推施工的杆系有限元模型,分析了梁体在顶推过程中的反力、内力和变形的变化规律,找出了主梁的最不利受力工况。基于该模型,对施工过程中梁体横截面温差引起的梁体反力、内力和变形的变化规律进行了探讨。最后,采用ANSYS软件中的混合梁-壳单元法,对前述主梁的最不利受力工况进行精细有限元分析,得到了支承点附近各板件的应力状态。进一步地,讨论了底板、腹板、横隔板、支承点处横肋和纵肋等板件厚度等对梁体局部受力性能的影响,并给出了改进方案。更多还原

【Abstract】 Incremental launching method is increasingly used in the constrution of steel box girder bridge, whereas there are several pressing issues. Fuming bridge, a cable-stayed bridge with steel box girder in Ningbo City, is taken as an example in this thesis. Some key technologies in the incremental lauching construction of it are discussed and studied, which provides a reference for the design and construction of similar bridge type.Firstly, this thesis describes the technologies of incremental launching construction. The reasons of the cumulative manufacturing errors of steel box girder are analyzed, and then the caculation method of secondary interal force caused by manufacturing errors is proposed. On this basis, the location of the temporary pier is optimized in a simplimied model to reduce the cumulative manufacturing errors.Secondly, a bar system FEM model is established to investigate the variation trend of the reaction force, internal force and deformation of the steel box girder during the incremental launching process, and the mose unfavorable loading state is identified. Based on the same model, the reaction force, internal force and deformation of the steel box girder caused by its cross-section temperature difference are studied.Finally, based on the mixed beam and shell elements method of ANSYS software, a precise analysis of the most unfavourable loading state of the steel box girder is carried out, and the stress distribution of each panel near the supporting point is obtained. Furthmore, the thickness of bottom, webs, diaphragms, transverse ribs and longitudinal ribs of the steel box girder which have great influences on its local stress state are discussed and several improving suggestions are put forwad.更多还原