【毕业论文】桥梁工程.doc

兰州交通大学毕业设计 土木工程学院 桥梁工程 土木076班 李小刚摘要 本毕业设计的对象为一座3×30m简支梁桥，该桥位于长寿北部新区，跨越桃花溪。桥梁平面位于直线段上，全长100米，宽度32米，设计荷载为公路-I级。主梁横向由14片T梁组成，梁高均为2.0m，两片梁之间设置60cm宽现浇湿接缝。本桥采用桩柱式桥墩，直径1.5m的圆形截面墩柱及直径1.8m的圆形截面钻孔灌注桩，桩基础嵌入完整中风化基岩面5.4m以下；采用重力式U型桥台，桥台基础为直径1.5m的钻孔灌注桩基础。 桥梁上部结构采用Midas程序进行分析计算，分析模型为单片简支T梁，仅分析一片边梁，中梁偏安全的采用边梁的分析结果来进行验算。横向分布系数通过桥梁博士3.0计算完成。内力计算结果包括基本组合、长期组合及短期组合作用下的弯矩图、剪力图、最大应力图。根据内力计算结果，对主梁进行了承载能力及正常使用性能的验算。盖梁承载能力验算及裂缝宽度验算与抗剪验算、墩柱承载力验算及裂缝宽度验算、桩基承载力验算及裂缝宽度验算均由自编计算机程序计算完成，墩柱与桩基的水平位移及其它效应由桥梁博士3.0计算完成。 根据验算结果得出结论：设计的桥梁结构是安全、经济、合理的，并满足现行规范的要求。 关键词：桥梁；荷载组合；内力；验算；承载能力 Abstract The object in this graduation project is a simply supported three-span girder bridge ( 3×30m) in New Zone of Changshou North and straddles Taohua Stream. The bridge is straight on the plane with 100 metres in length and 32 meters in width.The bridge is a part of a highway which the design load is Highway-I-level. The main beam is made up of 14 T-beams that are 2.0m high and the adjacent beams are linked by pouring wet joint with 60cm in width between the two beams. Substructure is made up of circular section piers with a diameter of 1.5 and circular section bored pouring pile foundation with a diameter of 1.8 m, the pilings of foundation are embedded into the intack moderately differentiated rock with a depth of 5.4m. The concrete gravity abutment is 6.5m high with a type of U and supported by pile foundation. Analysis of superstructure in the bridge be done by using Midas Civil Trial 2006. Simply supported single T-beam is used as analysis model in the program, only one edge beam is analysed and the mid beam using the same result in analyzing on safe side. Transverse distributing coefficient can be exported by using Dr bridge 3.0. The calculations include bending moment diagram, shear force diagram and maximum stress under basic/long-term/short-term load combination. According to the calculations, checking of capacity and performance of normal use of the beam have been done. Checking of capacity/crack width/shear