芒稻河刚构-连续梁设计(根部截面高跨比117)

论文总字数：72786字

摘 要

预应力混凝土连续刚构桥与其它型式的梁桥相比，有外形尺寸小，桥下净空大，混凝土用量少，结构刚度好等优点。比如说与同等跨径的连续梁桥相比，由于桥墩承担一部分的弯矩，刚构桥的截面控制弯距相对减小，墩顶负弯矩明显小于同跨径连续梁桥，在墩梁固结共同工作下，可以充分降低跨中区域的梁高，减小主梁跨中截面尺寸，使恒载内力进一步减小，增大主桥的跨径。近年来，随着预应力混凝土技术的发展和悬臂施工方法的广泛应用，连续刚构桥得到了进一步的发展。

本设计为（77m 3×130m 82m）公路预应力混凝土连续刚构桥设计，主要针对已经给出的大跨度连续刚构桥的上部结构设计，由于时间有限，本设计主要针对上部结构，也就是主梁和桥面的设计。

本设计主要采用MIDAS分析软件来进行结构内力分析计算，期间也用了Autocad 和Excel进行辅助设计。全桥上部结构共分为167个单元，定义有27个施工阶段，先进行边跨合龙，再进行次中跨合龙，最后进行中跨合龙。

建好计算模型后，对结构进行内力分析计算，然后对预应力钢筋数量进行估计并配置钢筋，进行预应力损失和各项次内力计算，然后再进行荷载组合并检算主要控制截面的承载能力和变形情况。在做完所有计算后，绘制结构主要施工图，包括桥跨布置图、施工顺序图等，进行外文翻译，最后编制设计计算说明书和文档整理。

关键词：预应力混凝土，刚构桥，悬臂浇筑施工，设计

Abstract

Compared to the prestressed concrete continuous rigid frame bridge and other types of beam bridge, shape, small size, clearance under the bridge, less the amount of concrete structure stiffness good advantages. For example, compared with the same span continuous beam bridge, the pier bear part of the moment, the cross section of the rigid frame bridge control bending distance decreases relatively, pier top negative moment is obviously less than that of the same span continuous beam bridge, under the pier beam consolidation work can fully reduced cross region in the Department, reduce the cross beam section size, the dead load internal force is further reduced, increasing bridge span. In recent years, with the development of prestressed concrete technology and the wide application of cantilever construction method, the continuous rigid frame bridge has been further developed.

The design here is that of an (77m 3×130m 82m) spans of prestressed concrete continuous rigid frame bridge. It is intended for the superstructure design of the long-span continuous rigid frame bridge which has been given. Since time is limited，the design puts emphasis just on the top structure， that is to say， the main beam and the bridge floor.

This design mostly uses MIDAS to calculate the internal force, also used AutoCAD and Excel for-aided during the design. The entire bridge is discretized in 167 elements , the construction process is simulated with 27 construction stages, the side spans are closed at first, and then the edge span,finally the side

After the completion of the calculation model, analysis of the internal force of the structure, the amount of the steel bar is estimated and the collocation is done. After these processes, prestressing loss and the redundant internal forces are calculated, and then load combination, the bearing capability of beam’s main controlling section are checked. After all of the calculation, the construction drawings (including bridge span arrangement, construction procedure and so on), the translation of a foreign language article are completed. And the introduction of the design’s text is made at last.

KEY WORDS: prestressed concrete, rigid frame bridge, cantilever construction, design

目 录

摘 要 I

Abstract I

第一章 工程概况 2

1.1工程概况 2

1.2气象、水文 3

1.3地形地貌 4

第二章 桥梁总体布置及结构主要尺寸 5

2.1桥型布置及孔型划分 5

2.2截面形式及截面尺寸拟定 5

2.2.1梁高尺寸拟定 5

2.2.2横截面尺寸拟定 5

2.2.3 桥墩尺寸拟定 5

2.2.4 横隔板 5

2.3 单元划分 6

2.4 施工段的划分 6

第三章 主梁内力计算 7

3.1 Midas Civil单元划分 7

3.2 材料、边界及荷载数据 7

3.2.1材料特性值 7

3.2.2荷载信息及边界情况 7

3.2.3施工荷载 8

3.3恒载内力计算 8

3.4 成桥阶段内力计算 9

第四章 预应力钢束的估算与布置 11

4.1 计算原理 11

4.2 预应力筋的估算 13

第五章 预应力损失计算 14

5.1计算原理 14

5.1.1应力钢筋与管道间的摩擦引起的应力损失 14

5.1.2锚具变形、钢筋回缩和接缝压缩引起的应力损失 15

5.1.3 钢筋与台座间的温差引起的应力损失 16

5.1.4 混凝土弹性压缩引起的应力损失 16

5.1.5 钢筋松弛引起的应力损失 17

5.1.6混凝土的收缩和徐变引起的损失 18

5.2有效预应力值 23

第六章 次内力计算 28

6.1预加力引起的次内力 28

6.2墩台基础沉降引起的次内力 30

6.3收缩徐变引起的次内力 32

6.4 温度引起的次内力 36

第七章 内力组合 41

7.1 承载能力极限状态下内力组合 41

7.2 正常使用极限状态下内力组合 42

7.3 弹性阶段截面应力计算时的荷载组合 43

7.4荷载组合 43

第八章 截面验算 48

8.1短暂状况验算 48

8.2持久状况验算 50

8.2.1正常使用极限状态 50

8.2.2承载能力极限状态 54

参考文献 61

致 谢 62

剩余内容已隐藏，请支付后下载全文，论文总字数：72786字