Numerical Simulation Of Characteristic Of Wind Pressure Distribution On Long Span Cable-stayed Bridge

Wind damage is the most common and one of the most serious natural disasters in the word. It not only frequently damages a large number of engineering structure, but also gives us the human social activities and daily life which caused serious influence, resulting in the human society huge losses of life and property. Especially as to the bridge structure, because it is occurred frequently that bridge structure is destroyed seriously by wind force. Currently, global planning and construction of cross-sea and islands marked the world bridge engineering entered the new period again, but our country has a large part of the planning and construction of the bridge is across the gulf coast and channel which are large span bridges. Therefore, along with the increase of bridge span which leads to structure more and more gentle, more and more prone to vibration, especially the structural vibration induced by the wind. wind load has become one of the most important control factors affecting the safety of the bridge structure, the safety problems of bridge is also more attention by people under the action of the wind, wind resistance of large span cable-stayed bridge become the primary problem to solve by bridge experts and scholars. Under the support of western transportation project and natural foundation of Hunan Province, biased on Donating Lake Bridge of Yueyang as the research background, by field measurement and numerical simulation(CFD) technology with the research methods of combining bridge wind field characteristics, To study and analyze wind field characteristics of bridge, under the action of wind pressure distribution and aerodynamic parameters of bridge tower(the main tower) and main girder cross section in the wind load. It provides some reference for wind-resistant design studies of long-span bridge structure in future. The main work content of research are as follows:1. Utilizing the numerical analysis of Matlab software for bridge tower and bridge deck synchronous acquisition of wind speed data was analyzed, getting wind load calculation of the average wind speed profile, the exponential fitting, turbulence intensity, gust factor, to infer the bridge sitting in the roughness of the surface belong to categories.2. Laying pressure transmission pipe, wind pressure data acquisition and data processing of bridge tower, using the FLUENT software processor Gambit to establish the 3d geometric model of the bridge tower which is close to the actual size, 3d of flow around of bridge tower is simulated, results from the simulation and observation were compared, to verify the reliability and feasibility of numerical simulation method in this paper. And on this basis, Aerodynamic force component of bridge tower under different wind speed and direction as well as the flow field disturbances of bridge tower are simulated, which obtained change regularity of aerodynamic force component of bridge tower and wind pressure or vector field of flow around tower column under different wind speed and direction. And the results are researched and analyzed.3. According to the existing aerodynamic force component of bridge deck, using the FLUENT software processor Gambit to establish the 2d geometric model of the bridge deck which is close to the actual size,Under the condition of uniform flow, 2d of flow around of main girder is simulated, results from the simulation and observation were compared, to verify the reliability and feasibility of numerical simulation method in this paper, And on this basis, Aerodynamic force component of bridge deck under different attack angle is simulated, which obtained change regularity of aerodynamic force component of bridge deck and wind pressure or vector field of flow around it under different attack angle. And the results are researched and analyzed.