The Study Of Aerodynamic Parameter For Steel Truss Girder Of Long Span Railway Bridge

In China, With the ever-increasing of the bridge span, Actual code of railway bridge can no longer meet the need of the long span railway bridge in calculation of wind load, and it’s needed to be supplemented and completed immediately. There are few specialized researches on aerodynamic parameters at home and abroad, and mainly for highway bridge. It can’t be directly used in the construction of the China’s long span railway bridges.Most of the girder of China’s railway bridge is truss forms, so it’s necessary to do some study on aerodynamic parameters of the truss section by testing.This thesis take Anqing Yangtze river railway bridge as the basic object, and study the three-component force coefficient of various truss-form sections. the main contents are as follows:First of all, the thesis stated the meaning and calculation methods of the three-component force and coefficient about wind load, summed up the characteristics and impact parameters of truss girder under the static wind load, and mentioned the designing and testing methods of the segment model.Secondly, various truss-form sections have been tested in wind tunnel, obtained the three-component force coefficient by calculating, and verified the effectiveness of the data.Then the thesis did separately analysis on different parameters which are width, height, aspect ratio, the number of truss, the solidity ratio of truss, and the inclination of truss, and summed up the influence of truss girder’s three-component force coefficient by changing each parameter.Finally, This thesis studied the calculation methods of wind load on girder in different countries’s codes, and made the calculated values and experimental values compared to come to the applicability of the truss girder’s calculations of wind load on China’s railway bridge.Then it discussed the appropriate calculation methods of wind load for truss girder in the code of China’s railway bridge.