桥梁设计本科毕业论文 下载本文

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毕业设计(论文)专用纸

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目 录

1设计资料 ............................................................................................................................................ 3

1.1跨径 ........................................................................................................................................... 3 1.2桥面净空 ................................................................................................................................ 3 1.3设计荷载: ............................................................................................................................ 3 1.4材料 ........................................................................................................................................ 3 1.5结构设计 ................................................................................................................................ 3 1.6 设计参数 ............................................................................................................................... 3 2造型式及尺寸选定 ............................................................................................................................ 4 3空心板毛截面几何特性计算 ............................................................................................................ 5 4作用效应计算 .................................................................................................................................... 5

4.1永久作用效应计算 ................................................................................................................ 5 4.1.1空心板自重(一期恒载) ................................................................................................... 5 4.1.2桥面系自重g2(二期恒载) ............................................................................................... 5 4.1.3恒载内力计算 ....................................................................................................................... 5 4.2基本可变荷载(活载)产生的内力 .................................................................................... 6 4.2.1汽车荷载横向分布系数计算 ............................................................................................ 6 4.3作用效应组合 ...................................................................................................................... 13 5预应力钢筋的设计 .......................................................................................................................... 15

5.1预应力钢筋截面积的估算 .................................................................................................. 15 5.2预应力钢筋的布置 .............................................................................................................. 17 6换算截面几何特性计算 .................................................................................................................. 18

6.1换算截面面积 ...................................................................................................................... 18 6.2换算截面重心位置 .............................................................................................................. 18 7承载能力极限状态计算 .................................................................................................................. 19

7.1跨中截面正截面抗弯承载力计算 ...................................................................................... 19 7.2斜截面抗剪承载力计算 ...................................................................................................... 20 8预应力损失计算 .............................................................................................................................. 24

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毕业设计(论文)专用纸

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8.1摩擦损失σ

l1 ......................................................................................................................... 24

l2 .......................................................................... 24

8.2锚具变形、回缩引起的预应力损失σ

8.3混凝土弹性压缩引起的预应力损失?l4 ........................................................................... 24 8.4预应力钢绞线由于应力松弛引起的预应力损失σ

l5 ..................................................... 25

8.5混凝土收缩、徐变引起的预应力损失?l6 ....................................................................... 26 8.6预应力损失组合设计 .......................................................................................................... 28 9正常使用极限状态计算 .................................................................................................................. 29

9.1正截面抗裂性验算 .............................................................................................................. 29 9.2斜截面抗裂性验算 .............................................................................................................. 32 10变形计算 ........................................................................................................................................ 38

10.1正常使用阶段的挠度计算 ................................................................................................ 38 10.2预加应力引起的反拱计算及预拱度设置 ........................................................................ 38 11短暂状况应力验算 ........................................................................................................................ 40

11.1跨中截面 ............................................................................................................................ 40 11.2 1/4截面 ............................................................................................................................ 42 10.3支点截面 ............................................................................................................................ 43 12持久状况应力验算 ........................................................................................................................ 45

12.1跨中截面混凝土正压应力?kc的验算 ............................................................................. 45 12.2跨中截面预应力钢绞线拉应力?p的验算 ...................................................................... 45 12.3斜截面主应力验算 ............................................................................................................ 46 13 最小配筋率复核 ........................................................................................................................... 50 结论与展望 ......................................................................................................................................... 51 致 谢 ................................................................................................................................................... 52 设计依据及参考书 ............................................................................................................................. 53 附录 图纸 ....................................................................................................................................... 54

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毕业设计(论文)专用纸

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1设计资料

1.1跨径

标准跨径: 16.00m。 计算跨径: 15.40m。 主梁全长:15.96m。

1.2桥面净空

净10.0m+2×0.5m。

采用混凝土防撞栏杆,线荷载7.5 KN/m。

1.3设计荷载:

公路—II级汽车荷载。

1.4材料

预应力钢筋1×7股钢绞线,直径15.2mm。 非预应力钢筋采用HRB335,R235。 空心板块混凝土采用C40混泥土。 铰缝采用C40SCM灌浆料以加强铰缝。

桥面铺装为8cm厚C40防水砼(S6)+ 4cm中粒式沥青砼+3cm细粒式沥青砼。 栏杆采用C25号混凝土。

1.5结构设计

本空心板按部分预应力混凝土A类构件设计。

横坡为1.5%单向横坡,各板均斜置,横坡由下部结构调整。 艺:预制预应力空心板采用后张法施工工艺。

1.6 设计参数

相对湿度为55%。计算混凝土收缩、徐变引起的预应力损失时传力锚固龄期为7d; 桥梁安全等级为二级,环境条件Ⅱ类。

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