摘要：这个设计用有限元软件Midas设计一座4*40m先简支后连续的预应力混凝土连续梁桥。一开始用国家现行规范以及同类型的设计进行截面选择。使用传统方式计算出二期荷载、横向分布系数。然后利用有限元软件Midas建立有限元模型，运行分析，进行荷载组合，并按照要求对主梁所需的钢束数进行估算。最后预应力梁应满足正常使用极限状态的应力要求和承载能力极限状态的强度要求。

关键词：预应力混凝土T梁；有限元；先简支后连续；迈达斯

The design of NiuJia river bridge

ABSTRACT：This design uses finite element software Midas to design a 4*40m pre-stressed concrete continuous beam bridge that is simply supported and then continuous. At the beginning, cross-section selection was made using the current national norms and designs of the same type. The second-phase loading and lateral distribution coefficients were calculated using the traditional method. Then use the finite element software Midas to build a finite element model, run the analysis, perform the load combination, and estimate the number of strands required for the main beam as required. The final pre-stressed beam should meet the stress requirements of the normal service limit state and the strength requirements of the limit state of the bearing capacity.

KEY WORDS：Midas software; Pre-stressed Concrete T-beam; finite element; Simple-Beam-to-Continuous;

目录

1绪论 1

1.1 预应力混凝土连续梁桥概述 1

1.2 毕业设计的目的与概述 1

2设计资料 3

2.1 桥梁概况 3

2.2 设计参数 3

2.3 技术条件 3

2.4 设计要求 4

2.5 规范标准 4

3.桥跨总体布置及结构尺寸拟定 5

3.1 本桥主要材料 5

3.2 尺寸拟定 5

3.3 桥孔分跨 6

3.4 截面形式 6

3.4.1 立截面 6

3.4.2 横截面 7

3.5 梁高 7

3.6 细部尺寸 7

4.方案比选 9

4.1 构思宗旨 9

5.荷载内力计算 11

5.1 恒载内力计算 11

5.1.1全桥节段划分 11

5.1.2计算模型 11

5.1.3计算内容 12

5.2 活载内力计算 15

5.2.1汽车冲击系数