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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