Wind-Induced Buffrting Analysis For Long-Span Highway Steel Truss Arch Bridge In Time Domain

With the rapid development of steel arch bridge technology, long-span steel arch bridge constantly increasing constructed, wind-induced vibration problems for this kind of bridges will become more and more prominent. Based on wind tunnel tests and spatial finite element modal analysis, this paper has systematically studied on wind-induced vibration of steel truss arch bridge.The main work of this detailed study covers the simulation of fluctuating wind field,the wind load at main arch,analysis of static wind load and buffeting in time domain.Taking a long-span highway steel truss arch bridge as the background of the project, the wind-induced vibration of the bridge at operational and constructed state is analyzed.The main research and findings are focused on the following aspects:1. According to the fluctuational characteristics of natural wind,based on the Constant Amlitude Wave Superposition(CAWS), considering that the wind speed spectrum is vary with the direction of the bridge span and the height of arch rib, the simulation for the turbulent wind speed field at the bridge site is achieved,moreover,its reliability has been examined.2. Applied with the general purpose finite element sofeware ANSYS introducing into the beam element construction dimensional finite element model for calculating,the vibration characteristic in the constructed and operational phase of bridge are analyzed, the frequences and vibration modes about the bridge are showed.3. Aerodynamic parameters from main beam at deck are been achieved by means of section model of static wind tunnel tests.In order to study wind load distribution and truss interference of main arch separated into several sections,the wind tunnel tests for measuring force are carried on the separated main arch,then receive the static coefficient from all sections of main arch,it provides a effective method to supplied wind loads to truss arch.4. A detailed analysis of the steel truss arch bridge is carried out at the constructed and operational phases, the response of static wind and buffeting loads are obtained,thus that can receive the features of wind-induced vibration for the bridge at the designed wind speed,it can be as a reference for this sort of bridges. Furthermore,on the basis of competitive analysis,the study is carried out about the influence from lift and moment force of wind loads on wind-induced response of arch bridge.In the last,the research achievements of this article are summarized, besides, the further research orientations are indicated.