发布时间 : 星期一 文章20m简支T梁毕业设计要点更新完毕开始阅读2b543f5af02d2af90242a8956bec0975f465a4ae
毕 业 论 文
简支T形桥梁设计
班 级: 土木工程系11届道桥1班 学 生: 陈土平(1135131103) 指导教师: 林煌老师
目录
一、 基本设计资料 ................................................................................................................................................. 2 二、 主梁内力计算 ................................................................................................................................................. 3
2.1. 恒载内力 ................................................................................................................................................... 3
2.1.1. 恒载集度 ...................................................................................................................................... 3 2.1.2. 荷载内力 .................................................................................................................................. 3 2.2. 荷载横向分布系数计算 ............................................................................................................................ 4
2.2.1. 支点荷载横向分布系数 ............................................................................................................... 4 2.2.2. 跨中荷载横向分布系数 ............................................................................................................... 5 2.3. 汽车冲击力系数 ...................................................................................................................................... 7 2.4. 活载内力 ................................................................................................................................................. 7
2.4.1. 计算公路-I级车道荷载的标准值 ........................................................................................... 7 2.4.2. L/2处最大内力计算 ................................................................................................................. 8 2.4.3. L/4处最大内力计算 ............................................................................................................... 10 2.4.4. 支点处最大剪力计算 .............................................................................................................. 12 2.5. 作用效应组合 ........................................................................................................................................ 14 三、 行车道板计算 ............................................................................................................................................... 16
3.1恒载内力计算(以纵向1m宽的板条进行计算) ................................................................................. 16 3.2. 车辆荷载的内力计算 .............................................................................................................................. 16 3.3. 作用效应组合 .......................................................................................................................................... 18 四、 配置钢筋及验算............................................................................................................................................ 19
4.1主梁钢筋筋计算 ........................................................................................................................................ 19
4.1.1. 计算主梁受拉钢筋的配置 ........................................................................................................... 19 4.1.2. 主筋正截面抗弯验算 ................................................................................................................... 20 4.1.3. 主梁受斜筋配置 ........................................................................................................................... 21 4.1.4. 主筋弯起后斜截面抗弯强度的验算 ........................................................................................... 23 4.1.5. 计算主梁箍筋配置 ....................................................................................................................... 24 4.2. 斜截面抗剪验算 ...................................................................................................................................... 25 4.3. 裂缝宽度验算 .......................................................................................................................................... 26 4.4. 挠度验算 ................................................................................................................................................. 27 4.5. 设置预拱度.............................................................................................................................................. 30 毕业设计总结 ......................................................................................................................................................... 31 结束语 ..................................................................................................................................................................... 32 主要参考资料 ......................................................................................................................................................... 33
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一、基本设计资料
1. 标准跨径:20m.
2. 桥面净宽:A.净7.5+2×1.0
3. 汽车荷载:公路Ⅰ级;人行道和栏杆自重线密度按照单侧5KN/m计算。 4. 人群荷载:3.5KN/㎡ 5. 主要材料
混凝土:混凝土简支T形梁及横隔梁采用C40混凝土,桥面铺装上层采用0.03m沥青混凝土,下层为厚0.06~0.13m的C30混凝土,沥青混凝土重度按23KNm计,混凝土重度(铺装层)按25KNm3计。
6. 钢材:箍筋采用HPB300,受力筋采用HRB335。
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由上图,本桥共由5片T形梁组成,单片T形梁高1.50m,宽1.9m,桥上横坡度为2.0%,坡度由C30混凝土桥面铺装所控制;设有五根横隔梁。
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二、主梁内力计算
2.1. 恒载内力
2.1.1. 恒载集度
(1)主梁肋:
g1?[0.18?1.5?0.15?(1.9?0.18)]?25?12.08KN/m
(2)横隔梁(边主梁):
g2?[(1.13?0.150?(1.9?0.18)/2?0.18?5?25]/19.5?0.97KN/m
(3)横隔梁(中主梁):
g3?2?0.97?1.94KN/m
(4)桥面铺装层:
g4?[0.03?7.5?23?(0.06?0.13)/2?7.5?25]?5?4.06KN/m
(5)栏杆和人行道:
g5?5?2/5?2.00KN/m
(6)边主梁全部集度恒载:
g边?g1?g2?g4?g5?12.08?0.97?4.6?2?19.65KN/m
(7)中主梁全部集度恒载:
g中?g1?g3?g4?g5?12.08?1.94?4.6?2?20.62KN/m
2.1.2. 荷载内力
上述计算结果说明,应该计算中主梁的横在内力为最大,但通常活载内力边主梁最大,经何在内力效应组合后,往往边主梁控制设计,因此,本算例只计算边主梁的恒载内力。
Mx?4Mmax/l2?x?(l?x)?gl/2?x?g/2?x2?g/2x?(l?x)Qx?gl/2?g?x?g/2?(l?x)
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