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摘要
本次毕业设计主要是关于牛溪滩桥梁的结构设计计算，根据提供的地质材料和技术指标 做出技术经济合理的设计方案。
设计过程分为两部分：第一部分是上部结构计算，第二部分是下部结构计算。设计过 程中，通过分析桥梁结构在使用工程中的恒载及恒载作用，分别计算各主梁横向分布系数， 考虑不同的荷载安全系数进行荷载组合，将极限状态的两种内力组合结果作为估算钢束的 计算内力。估算出各截面的钢束后，按照一定要求将钢束布置好。然后进行截面强度验算、 应力验算及变形验算；第二部分进行墩柱、桩基础和桥台的设计计算，墩柱计算包括盖梁、 桥墩的计算；桩基础的计算包括桩长、桩的内力计算、桩的配筋计算；桥台的计算包括作 用计算等。对于墩柱、桩基础进行承载力验算、应力验算、裂缝验算、变形验算等。，对 于桥台则进行基础承载力验算、基底偏心距验算、基础稳定性验算、抗倾覆稳定性验算、 抗滑动稳定性验算四个部分的验算。若各项验算均满足设计要求，则设计通过。在设计过 程中，充分利用了 CAD、WORD、EXCEL 等。
本桥设计跨径为 25m 简支 T 型梁，桥面宽 16.25m,双向六车道，环境类别为 II 类。 关键词：预应力简支 T 形梁；应力计算；钢束布置；施工图；极限状态；验算
Simple supported T bridge with fabricated pre-stressed reinforced concrete
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The graduate design is mainly about the design of superstructure of Niu xi tan Pre-stressed concretegirder bridge. According with the geological condition provided by design situation and the local condition . Through analyzing internal force of the dead loads and live loads at the stage of using and considering the different safety factor of the force I calculate the design value of combination for action effects of the limit states and estimate the area of steel of the bridge. As the steel is assigned reasonably, we should imitate the construction process secondly and consider the affect of the pre-stressed steel, then calculate the combined force of the limited condition again, which is for checking the force of the construction stage and the using stage. Lasting situation sectional ultimate limit state, the steel beam pre-stressing loss estimate, stress checking, checking crack resistance, the main beam deformation calculation and local bearing checking Anchorage area。If the force can meet the need and the design is reasonable then the design is advisable. During the process of the design I make good use of the software such as CAD、WORD and EXCELL to optimize my design.The spans of the bridge are 60+3×100+60m,which the main beam is respective designed, each suit has one box one room and six traffic ways, the width of the bridge surface is 16.25m.
Key Words: Grade separatedPre-stressed concretegirder bridge；Stress calculation; Construction drawing ； Beam layout Limit states；Checking | 
