毕业设计（论文）-预应力混凝土先简支后续梁桥设计.doc

预应力混凝土先简支后连续梁桥设计 摘要 本次设计是有关预应力混凝土连续箱梁桥设计，桥梁跨径35m+50m+35m，先简支后连续结构梁桥在高等级公路中得到了越来越多的使用，渐代替了原来单一的简支梁桥或连续梁桥，它兼顾了简支梁桥和连续梁桥的优点。而体系转化在先简支后连续梁桥施工中具有重要意义。箱梁吊装完成后，预制梁非连续端安装在永久支座上，连续端安装在临时支座上，此时墩顶永久支座暂不受力，由临时支座参与结构受力，支撑箱梁，每跨之间为简支体系，待体系转换完成后，形成整体的连续结构体系，再将临时支座拆除，使原来布置在墩顶中间的永久支座参与受力。? 简支转连续体系转换的主要施工工序是先连接桥面板钢筋、端横梁钢筋及浇筑端横梁混凝土，再逐次连接连续接头段及设置接头钢束波纹管并穿束、绑扎中横梁钢筋、浇筑连续接头段和与顶板钢束同长范围内的湿接缝，待混凝土达到设计强度要求后，进行墩顶钢束张拉及压浆，再由跨中向支点浇筑剩余部分的湿接缝，最后拆除临时支座，使梁支承在永久支座上，经支座转换形成连续梁体系。?简支转连续梁桥体系形成的关键是结构从简支状态转换为连续状态，包括混凝土现浇段施工、顶板负弯矩预应力张拉和临时支座的拆除。其中连续端浇筑及张拉压浆顺序采用对称浇筑、对称张拉。 本次毕业设计主梁采用等高度箱型截面，横向布置4片箱梁。设计车速100Km/h，3车道，桥梁总宽:0.5+3×3.8+0.5=12.4m。桥轴线为直线，道路纵坡3%，横向坡度1.5%。设计荷载标准为公路Ⅰ级。由于计算过程中有较多的数据处理，如采用手算较为繁琐，且准确性得不到保证，因此采用计算机辅助设计。本次设计采用了AUTOCAD、桥梁博士、EXCEL电子表格等软件，通过本次毕业设计，大幅提升了自己对办公软件及桥梁设计软件使用能力。 关键词：预应力混凝土连续梁桥 先简支后连续 桥梁博士 The design of prestressed concrete continuous box girder bridge design, bridge span 35m+50m+35m, simple supported continuous girder bridge structure in high grade highway obtained the more and more use, and gradually replaced the original single beam bridge and continuous beam bridge, which take into account the advantages of simply supported beam bridge and a continuous beam bridge. And the system transformation of the first simply supported continuous beam bridge construction has important significance. Box girder hoisting finished, the precast beam non continuous terminal installed on the permanent support, continuous terminal installation in the temporary support, at the pier top permanent support temporarily not by force, by the temporary support in the structure stress, supporting the box beam, each cross between simply supported system, until after the completion of the system transformation, the formation of the overall continuous structure system, then the demolition of temporary support, so that the original layout in the pier top in the middle of the permanentsupport participation by force. Simply supported continuous system switch of main construction procedure is to connect