随着西部大开发战略的深入，跨越山区峡谷地形的桁架主梁大跨度悬索桥越来越多的被修建。而峡谷桥址处的风场具有显著的时空不均匀特性，用常规试验手段来分析大桥的风致响应将会产生较大偏差，而基于线性自激力理论的气动稳定评价标准也不再适用。本课题通过典型峡谷桥址风场实测、CFD数值模拟以及地形模拟风洞试验系统研究峡谷风场特性，建立适合桥梁设计的峡谷风场参数取值模型。通过大小比例节段模型以及安装在真实峡谷地形模型中的拉条模型测压试验，层层递进，建立考虑峡谷风场影响的桁架主梁自激力展向相关性表达式。利用节段模型强迫振动数值模拟和风洞试验，系统研究桁架主梁非线性自激气力随振幅及相位变化的规律，建立桁架主梁断面非线性自激力模型，进一步发展大跨度桥梁三维非线性颤振分析的实用理论和方法。探索山区紊流风场桥梁抗风设计合理的的评价准则，为山区大跨桥梁的抗风设计提供理论依据。

With the deepening of the western development strategy, more and more large span suspension bridge across the mountainous valley terrain with truss girder is being built. The wind field at the valley bridge site has a remarkable spatial and temporal inhomogeneity. The derivative of the beam measured by conventional test is difficult to reflect the influence of the turbulent wind field in the valley,large deviation will appear using it to analyze the wind-induced response of the main truss girder of the large span bridge. Also, the standard of aerodynamic stability evaluation based on the theory of linear self excitation is no longer applicable..In this study, we studied the wind field characteristics of valley by means of wind field measurement, CFD numerical simulation and wind tunnel test of real valley and series of simple valley models. Mathematical models that suitable for the wind parameters around bridge will be established at the same time. Through the pressure measurement test by taut strip model installed in the real valley terrain model.The correlation expression of the self excited force of a truss girder considering the influence of the wind field of the valley is established. By using forced vibration test of section model, the nonlinear self excited force of truss girder is studied systematically, and the nonlinear self excited force model of truss main girder section is established. The practical theory and method for three-dimensional nonlinear flutter analysis of long-span bridges have been further developed. The evaluation criteria of wind resistant safety for bridge in mountainous valley will be established which theoretical basis for wind resistance design of large span bridge in mountain area.