摘要：本设计桥梁属于跨江工程，位于浙江省省道公路上，地势较平坦。是一座新建桥梁（包括简支引桥）。该桥起讫桩号为K0+140～K0+420，全长280m。考虑到桥梁的实际情况，选用连续箱梁的结构进行设计。61737

连续梁在恒活载作用下，产生的支点负弯矩可以适当抵消跨中的正弯矩，使内力分布比较均匀，因而可以减小梁高增大桥面净空，节省材料，且刚度大，整体性好，超载能力大，安全度大，桥面伸缩缝少，因为跨中截面的弯矩减小，使得桥跨可以增大。并且预应力混凝土连续梁桥由于结构受力性能好、伸缩缝少、变形小、行车平顺舒适、造型简洁美观、养护工程量小、抗震能力强而成为最富有竞争力的主要桥型之一。

箱形截面由于具有良好的结构性能，因而在现代各种桥梁中得到广泛的应用。箱形截面抗扭度大，结构在施工与使用过程中都有良好的稳定性。

本桥设计为三跨预应力混凝土连续梁桥，桥长(40+70+40) 。采用变截面箱型梁，用悬臂施工法进行施工，双柱式桥墩，基础为钻孔灌注桩基础。

毕业论文关键词: 连续梁桥;箱形截面;双柱式桥墩;迈达斯

 National highway 104 deqing period of reconstruction project

 Abstract： This design belongs to engineering across the river bridge, located in the zhejiang provincial highway, the topography is flat. Is a new bridge (including simply-supported bridge approach). The bridge and the pile number of K0 + 140 ~ K0 + 420, the total length of 280 m. Considering the actual situation of the bridge, with continuous box girder structure design.

  Continuous beam under the action of live load constant, produce the fulcrum of negative bending moment can be offset across the appropriate positive bending moment, make the internal force distribution is evener, thus can reduce trabecular high increase of bridge deck is clear, save material, and big stiffness, good entirety, large overload capacity, safety, less bridge expansion joints, because of the cross section in the bending moment decreases, and makes the bridge span can be increased. And pre stressed concrete continuous girder bridge structure performance is good, less expansion joints, small deformation, driving smooth and comfortable, beautiful modelling concise, maintenance quantity is small, earthquake resistant capability is strong and become the most competitive one of the main bridge.

  Box section due to the good structural performance, and therefore has been widely used in modern all kinds of Bridges. Box section torsion al degrees, the structure is in the process of construction and the use has good stability.

This bridge is designed to three span pre stressed concrete continuous girder bridge, long bridge (40 + 70 + 40). Using variable cross-section box beam, the cantilever construction method for the construction, double column pier， foundation for the bored piles foundation.

Keywords: continuous girder bridge; Box section; Double column pier; Midas

 目 录

1. 原始资料 1

1.1 桥梁概况： 1

1.1.1 设计参数： 1

1.1.2 技术条件： 1

2. 方案比选 2

2.1 简支梁桥方案 2

2.2 中承式钢筋混凝土拱桥桥方案 3

2.3 连续梁桥方案 3

2.4 方案比较 4

2.5 选用考虑及选用的结果 4

3 总体布置及主要尺寸 5