频域法分析大跨度双管悬索管桥风抖振影响

Applying Frequency Domain Method to Analyze Wind Buffeting Effect on Large Span Suspension Bridge for Laying Double Pipelines

桥梁风抖振会使杆件的接头和支座等构造细节发生疲劳破坏。文章运用频域法对一座跨度360 m双管上下布置的悬索管桥进行风抖振影响分析。结果表明,在桥梁设计基准风速条件下,跨中侧向位移达到2.639 m,竖向位移达到0.466 m,扭转角为0.04°,管道最大弯曲应力达到58.3 MPa,拉索最大应力达到255.7 MPa,主缆最大应力达到311MPa。据此认为管桥各部分的应力均不大,满足要求;位移是设计的主要考虑因素,应设置共轭索或用斜向风索代替共轭索来控制管桥的竖向位移。

Wind buffeting effect on bridge will cause fatigue failure of the structural details such as rod joints and supports.The frequency domain method is applied to analyze the wind buffeting effect on a 360 m long span suspension bridge for laying double pipelines on upper and down layers.The results show that under reference wind velocity,the lateral displacement at the mid-span is 2.639 m,the vertical displacement is 0.466 m,the torsional angle is 0.04°,the maximum bending stress of the pipeline is 58.3 MPa,the maximum stress of the stay cable is 255.7 MPa,the maximum stress of the main cable is 311 MPa.Based on these data,it is considered that the stresses in all parts of this pipeline bridge are not high and meet design requirements;the displacement is the main factor in the design consideration;conjugate cables or oblique wind cables for replacing conjugate cables should be set up to control the vertical displacements of the pipeline bridge.