基于CFD方法的波浪作用下海域人行桥受力特性分析

Mechanical Analysis of Offshore Footbridge under Wave Action Based on CFD Method

南方地区跨海人行景观桥梁桥面标高较低,遭遇风暴潮时可能受到波浪冲击,准确计算桥梁上部结构受到的波浪力对桥梁防灾减灾设计具有重要的工程价值。该文以某海域人行景观桥为例,采用CFD方法对比不同桥梁断面在极端波浪力作用下受力特性,研究结果表明:在波浪冲击梁体初期,箱梁受到的竖向和水平波浪力最大,鱼腹梁受力较平稳;当受力稳定后,鱼腹梁受到的上托力最大,T梁最小;箱梁受到的下覆力最大,鱼腹梁最小。通过结构计算可知:箱梁主纵筋配筋率最大,T梁整体受力较差;鱼腹梁受力合理且线条流畅美观,推荐选用鱼腹梁断面作为海域人行景观桥梁断面。

Since the deck elevation of the offshore footbridge in southern China is lower,it may be affected by wave impact when it encounters storm surge.How to accurately calculate the wave force of the bridge superstructure is of great engineering value to the disaster prevention and mitigation design.In this paper,an offshore footbridge is taken as an example.The CFD method is used to compare the mechanical characteristics of different bridge sections under the action of extreme wave forces.The research results show that in the fluctuation period,the vertical and horizontal wave forces on the box girder are the largest,and the force on the fish-belly beam is stable.In the stable period,the upper pull force on the fish-belly beam is the largest and the T beam’s is the smallest.The box beam suffers the greatest overburden,and the fish-belly beam the least.Through structural calculation,it can be seen that the main longitudinal reinforcement ratio of box girder is the largest,and the overall force of T beam structure is poor.The section of the fish-belly beam has reasonable force and smooth and beautiful lines.It is recommended to choose fish-belly section as the section of the offshore footbridge.