Research On The Stability Of Continuous Rigid-frame Bridge With High Pier And Large-span

The continual rigid frame bridge with high pier and long span was widespread used because of the feature : explicit about force;driving unimpeded;the mature technique of construction etc.Especially for the large bridge with high pier, it is favoured by the builder of freeway in mountainous area because of using flexibility of thin wall pier to adapt all kinds of effect.This pier belongs to compression-bending component in theoretical design,actually,the pier existing initial defect,adding other factor's affects which made it's stability more complex. Based the backgrounds on the Ye Sanhe Bridge, the article has analysised the high pier self-stability, the biggest cantilever state's stability and the entire bridge's stability. The main research content and the achievement include:In the limit of elasticity, it has inferred the critical load formua about variable cross-section high pier's self-stability and the biggest cantilever state's stability in continual rigid frame bridge of double thin wall and high pier by the Ritz method, and drawed up a calculate procedure which provided one quick computational method for this kind of bridge stable's question.The large Finite Element Software ANSYS was used to analysis the stability about the Ye Sanhe bridge by establishing three-dimensional finite element model for the high pier, the biggest cantilever state and the finished bridge state.It has analysed the effect to the bridge's stability which separately considered initial displacement of the pier,initial offset of the load on the top of pier,the impact of wind load , differenal temperature effect of the sunshine and suspended wagon droped, has obtained the rule how influence to the stable of bridge by each kind of flaw.In the calculation, it has discussed and analysised the effect of the bridge's stability with thoughting the concrete's shrinkage and creep and the temperature over the structure.It also has analysised the Ye Sanhe Bridge's stability with the harmful combination of loads and cauculated the stability of the Ye Sanhe Bridge in the harmful combination of loads.The results provide the theory instruction for the problem of stability of the Ye Sanhe Bridge and the reference for the research to this kind of bridge's stability and the bridge's stability which considered the initial flaw.