简支变连续刚构小箱梁桥墩结构施工过程仿真分析

某城市快速环路采用高架与轨道一体化建设,上层桥梁采用简支变连续刚构小箱梁的结构形式,因施工过程中桥墩盖梁存在截面变化和体系转换,其墩梁固结部分的受力复杂。采用三维实体单元分析了一体化框架墩特别是盖梁在各个施工阶段的应力分布情况,并得到一些结论。分析表明,在该类结构设计时应注意盖梁钢束的张拉顺序和支架的拆除时机,尤其应注意加强中墩附近边梁剪扭钢筋的设置。

Simulation Analysis for Construction Procedures of Rigid-frame Bridge Formed from Simple Supported Small Box-girder

The construction of the fast ring road of one city uses double-level viaduct for the integrated viaduct and rail. The upper level structure adopts the rigid-frame formed from simple supported small box-girder. During the viaduct construction, the pier coping exists changes in cross-section and struc- tural system transformation, and the rigid part between the girder and the pier structure presents complicated mechanical behavior. This paper uses 3D solid element to analyze the stress distribution situation of the integrated frame pier especially the coping under different construction stage, and ob- tains some conclusions which have verified that the design of this kind of structure should pay atten- tion to tension sequence of pre-stressed tendons in the coping and the timing of its support frame re- moval, and reinforcement proportioning for shear and torsion in side girder adjacent to mid-pier as well.