摘
要 连续 T 梁混凝土是预应力桥梁中的一种，作为现代公路的主要结构形式，预应力混凝土连续梁桥结构在现今的公路工程中得到了广泛的应用。
本着“安全，经济，实用，美观”的设计理念，根据设计任务书和规范，对不同的桥型方案进行比较和选择，经由施工等诸多方面的考虑，确定预应力混凝土连续梁桥为最终设计方案。、 本设计预应力混凝土连续梁桥共分为三跨 30+30+30m，，桥面净宽为 0.50 m 栏杆+4×3.5 m车行道+0.50 m 栏杆，底板厚度从支座处的 1.5m 到跨中呈线性变化。腹板厚度在支座处为 0.2 m，跨中为 0.6 m，顶板厚度全桥一致。设计荷载为公路一级。
在本设计中，运用了桥梁设计软件桥梁博士，对桥梁结构（主要是上部结构）进行设计、模拟，并采用预制施工法对施工步骤加以模拟。同时对桥梁恒载、活载及徐变内力等进行分析计算，得出预应力钢束的预估值，进一步完善模型。最后，在各种荷载的组合下，对桥梁进行详细的有限元分析，并将分析结果与规范的要求进行对比，对主梁的应力、变形等进行验算，从而判断在设计荷载作用下该设计是否足够合理安全，以此得到完整的设计。经分析比较及验算表明该设计计算方法正确，内力分布合理，符合设计任务的要求。
关键词：
桥梁设计；预应力；T T 梁；连续梁三跨；桥梁博士
Abstract
Continuous T-beam concrete is one of the prestressed bridges. As the main structural form of modern highways, the prestressed concrete continuous beam bridge structure has been widely used in today"s highway projects. Based on the design concept of "safety, economy, practicality, and beauty", according to the design task book and specifications, different bridge schemes are compared and selected. After consideration of construction and other aspects, the prestressed concrete continuous beam bridge is determined as the final Design. , The prestressed concrete continuous beam bridge of this design is divided into three spans of 30 + 30 + 30m. The net width of the bridge deck is 0.50 m railings + 4 × 3.5 m driveway + 0.50 m railings. Linear to span. The thickness of the web is 0.2 m at the support and 0.6 m in the mid-span. The thickness of the roof is consistent across the bridge. The design load is highway level. In this design, the bridge design software Dr. Bridge was used to design and simulate the bridge structure (mainly the superstructure), and the prefabricated construction method was used to simulate the construction steps. At the same time, the dead load, live load and creep internal force of the bridge are analyzed and calculated to obtain the estimated value of the prestressed steel beam, and the model is further improved. Finally, under various load combinations, detailed finite element analysis is performed on the bridge, and the analysis results are compared with the requirements of the code, and the stress and deformation of the main beam are checked to determine the design under the design load. Is it reasonably secure enough to get a complete design. Analysis and comparison and check calculations show that the design calculation method is correct, the internal force distribution is reasonable, and meets the requirements of the design task. Keywords: bridge design; prestressing; T- - beam; continuous beam three- - span; bridge doctor
青兰高速公路大桥施工图设计
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目录 1
尺寸拟定与方案比选 ............................................................................................................................................. 5 1.1 设计条件 ....................................................................................................................................................... 5 1.2 方案比选 ....................................................................................................................................................... 5 2
设计资料及构造布置 ........................................................................................................................................... 13 2.1 设计资料 ..................................................................................................................................................... 13 2.2 构造布置 ..................................................................................................................................................... 14 3
横向分布系数及主梁内力计算 ........................................................................................................................... 17 3.1 永久作用效应计算 ..................................................................................................................................... 17 3.2 可变作用效应及横向分布系数计算 .......................................................................................................... 19 3.3 主梁内力计算 ............................................................................................................................................. 21 4
预应力钢束的估算及其布置 ............................................................................................................................... 24 4.1 跨中截面钢束的估算和确定 ..................................................................................................................... 24 4.2 预应力钢束布置 ......................................................................................................................................... 25 4.3 钢束的计算 ................................................................................................................................................. 26 4.4 非预应力钢筋截面积估算及布置 .............................................................................................................. 29 4.5
主梁各截面几何特性计算 ....................................................................................................................... 31 4.5.1 各控制截面几何特性计算 ...................................................................................................................... 31 截面特性截图 ............................................................................................................................... 错误!未定义书签。
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持久状况截面承载能力极限状态计算 ............................................................................................................... 32 6.1 正截面承载能力计算 ................................................................................................................................. 32 6.2 斜截面承载能力计算 ................................................................................................................................. 34 7
钢束预应力损失估算 ........................................................................................................................................... 37 8
应力验算 .............................................................................................................................................................. 45 8.1 短暂状况的正应力验算 ............................................................................................................................. 45 8.2 持久状况的正应力计算 ............................................................................................................................. 46 9
抗裂性验算 .......................................................................................................................................................... 47 9.1 作用短期效应组合作用下的正截面抗裂验算 .......................................................................................... 47 9.2 作用短期效应组合作用下的斜截面抗裂验算 .......................................................................................... 48 10
主梁变形计算..................................................................................................................................................... 51 活载最大最小位移频遇值 ................................................................................................................................ 51 结构竖向位移验算表格 .................................................................................................................................... 51 预拱度的设置 .................................................................................................................................................... 52 11
横隔梁的设计计算 ............................................................................................................................................. 52 11.1 确定作用在跨中横隔梁上的可变作用 .................................................................................................... 52 11.2 跨中横隔梁作用效应影响线 ................................................................................................................... 53 11.3 截面作用效应计算 ................................................................................................................................... 56 11.4 截面配筋计算 ........................................................................................................................................... 57 12
行车道板计算..................................................................................................................................................... 58 12.1 悬臂板荷载效应计算 ............................................................................................................................... 58 12.2 连续板荷载效应计算 ............................................................................................................................... 58 12.3 截面设计、配筋与承载力验算................................................................................................................ 61 13
支座计算 ............................................................................................................................................................ 62
青兰高速公路大桥施工图设计
4 13.1 确定支座平面尺寸 ................................................................................................................................... 62 13.2 确定支座厚度 ........................................................................................................................................... 63 13.3 验算支座的偏转情况 ............................................................................................................................... 63...