毕业设计（论文）题 目 大桥设计 摘要本毕业设计主要是关于预应力混凝土连续刚构桥上部结构的设计。预应力混凝土连续刚构桥以结构受力性能好、变形小、伸缩缝少、行车平顺舒适、造型简洁美观、养护工程量小、抗震能力强等而成为最富有竞争力的主要桥型之一。随着预应力技术的发展和不断完善，尤其是悬臂等先进施工方法的出现，更使预应力混凝土连续刚构桥更加充分的活跃在整个桥梁工程领域.本设计桥梁主桥跨径为 50m+90m+50m，主梁截面为单箱双室，桥面宽 11.5m，双向两车道，主梁采用悬臂浇筑法施工。在时间和个人能力有限的条件下，本次毕业设计没有具体涉及到下部结构、桥面铺装、竖向预应力的设计。仅对主梁结构详细设计，设计步骤如下：第一步，根据设计任务要求，依据现行公路桥梁设计规范,综合考虑桥位的地质、地形条件，经初选后提出了预应力混凝土连续刚构、上承式拱桥、斜拉桥三个比选桥型。按“功能、安全、经济、美观”的桥梁设计原则，比较三个方案的优缺点，最终选择连续刚构方案。第二步，参考规范和相关设计经验，确定主梁主要构造及细部尺寸。考虑到抗弯刚度及抗扭刚度的要求，及结构成桥阶段体系的转变，设计采用箱型梁。主梁高度采用近似于主梁纵向弯矩变化曲线的二次抛物线。第三步，主桥单元划分，进行有限元模拟分析成桥阶段结构内力，通过模拟分析得到的结果在正常使用极限状态下估算各截面纵向预应力筋面积，然后按照相关规范布置上、下缘纵向预应力束。关键词：预应力混凝土 连续刚构桥 悬臂浇筑 内力计算与验算IIABSTRACT IIIABSTRACT The graduation design is mainly about the superstructure of pre-stressed concrete continuous rigid frame bridge.Continuous rigid frame bridge of prestressed concrete become one of the main patterns of the most competition bridge,because of the perfect structure function,small strain,little expansion joint,smooth car driving,simple and pleasing shape,little engineering maintenance and superiority seismic capacity. With the development and improvement of prestress technology,especially the introduction of the modern cantilever construction,continuous rigid frame bridge of prestressed concrete act in the whole field of bridge engineering in full swing. The span of the main bridge are 50m + 90m + 50m, the bridge has single-box with double room of the cross section and 17m wide bridge deck and two traffic ways, The cast-in-cantilever is chosen to build the major girder. Due to the time and personal ability is limited, under the condition of the graduation design not do with substructure and deck construct and the design of the vertical prestress of the bridge. Only the detailed design of the spar boom, the design procedure is as follows: The first step, according to the design assignment and the present Highway Bridge Specifications, Take the geological and the landform of the bridge site for further analysis, after preliminary selection, three bridge type are presented, they are PC-continuous rigid frame bridge, cable-stayed bridge and PC-continuous beam-type bridge. Comparing their characters comprehensively, the PC-continuous rigid frame bridge is selected as the main design scheme by the philosophy of bridge design as “Practicability, Security, Economy, Beauty”, so the choose the PC-continuous rigid frame bridge .The second step, determine the main girder structure of details and size under the reference standard and related design experience,. Considering the flexural rigidity and the torsional rigidity of the bridge, and requirements of the force system change in the construction, s section is box beam. box birder goes as second-parabolic curve, which is generally similar to the change of continuous bridges bending moments along. The third step, the main unit division, the finite element simulation analysis internal force of the bridge in the construction, analysis compute steel area under serviceability limit state and lay out pre-stressing tendon of the upper and down limb under norm. IVKeywords: Pre-stressed concrete,continuous rigid frame bridge,desig.目录V目录摘要 .IABSTRACT .III1 绪论 .11.1 毕业设计的目的及意义 .11.2 预应力连续刚构桥特点 .11.2.1 设计特点 .11.2.2 受力特点 .11.2.3 构造特点 .22 结构设计方案 .32.1 设计资料 .32.1.1 桥梁名称 .32.1.2 基本资料 .32.1.3 设计标准 .42.1.4 主要材料 .42.1.5 设计依据 .