Wind Resistance Performance Research Of Long Span Arch Bridge On Construction Stage In Mountain Areas

With the development of modern construction technique and the application of new material, arch bridges which progress towards small rigidity, big flexility, long span and light weight are more sensitive to the action of the winds. Furthermore, the construction stability problem under wind loads has attracted more attention, especially for the long span arch bridge built in the mountains. In this paper, the Beipanjiang railway bridge is as to the engineering background, the bridge area is a typical western mountainous areas, complex topography led to a very complicated meteorological conditions. Therefore, wind-induced dynamic response and wind stability of structure are important to the safety of construction and operation, more attention should be paid to.This paper includes the following contents:1. It introduces the development status and the construction method of long span arch bridge at home and abroad detailedly, discusses the construction process of Beipanjiang railway bridge, and the necessity of research on wind resistance performance under the typical construction stages briefly.2. Based on the finite element software ANSYS, the thesis is designed to build three construction stage model including arch rib skeleton maximum cantilever, closure state to state framework and concrete outsourcing complete state, calculate the dynamic characteristics, and analyze the relationship of the transverse stiffness, vertical stiffness, torsional stiffness.3. Based on the obtained model wind tunnel test, the thesis is designed to obtain the static three component coefficients of two kinds of construction stage(reinforced largest cantilever state and the concrete outsourcing completed state). The author calculates the static wind force and buffeting response respectavely. In order to ensure the safety of the bridge in the stiff skeleton of the largest cantilever construction, it is suggested to apply oblique wind cable project in the middle span of3/8through calculation and comparison.4. According to the meteorological and hydrological data, the thesis is designed to calculate the design wind speed of the construction stage. Besides, it is also designed to built the wind tunnel test model, study the vortex induced vibration and the galloping phenomenon under the two construction stage through the section model test of reinforced largest cantilever state and the concrete outsourcing completed state. Because the arch rib steel skeleton construction the largest cantilever state is the most dangerous state of the bridge construction of wind, the full bridge aeroelastic model of the bridge is employed to analyze the performance of transverse wind stability, vortex induced vibration at the longest cantilever state.