A probability-based methodology for the analysis of fluctuating wind loads on cable-supported bridges

摘要考虑到风场、湍流波动和压力分布的固有复杂性，与风荷载相关的自然灾害情景的预测和模拟尤为困难。因此，无论是全尺寸试验还是风洞试验，都是推导动力载荷的关键。尽管研究界努力发展完善的技术，但预测有时可能与等效力或反应特性的记录值不同。这些差异与这门学科的实验性质有关。这一观察结果要求在所有风力工程应用中通过基于概率的方法对不确定性进行更全面的处理。大跨度缆索支撑桥梁是美国基础设施系统的骨干，位于主要公路网系统沿线，连接着全国各地的重要节点。该研究项目将提出并开发一种创新的方法来推导大跨度桥梁抖振问题的解决方案，这将涉及通过统计描述符直接表示不确定性来源，集中在空气动力输入和选定的结构参数上。将根据首席研究员可获得的数据和信息进行比较。风洞实验将用于证实气动和气动弹性力术语的不确定定义的相关性。值得强调的是，虽然颤振引起的倒塌可以从概率的角度重新解释为可靠性问题（即需要在统计上避免的情况），但颤振不能完全与唯一的安全指数相关，而是与失效和可用性条件相关

Abstract: CMS 0600575 The prediction and simulation of natural hazard scenarios associated with wind loading are particularly difficult in consideration of the inherent complexity of the wind field, turbulence fluctuations and pressure distributions. Therefore, experimentation, either full-scale or in wind tunnel, is vital for the derivation of the dynamic loading. Despite the efforts of the research community towards the development of refined techniques, predictions can, on occasion, differ from the recorded values of equivalent force or response characteristics. These discrepancies are associated with the experimental nature of this discipline. This observation calls for a more comprehensive treatment of uncertainty through probability-based methods in all wind engineering applications. Long-span cable-supported bridges are the backbone of the infrastructural system in the United States, located along the primary highway network system and connecting vital joints across the Nation. The research project will propose and develop an innovative approach for deriving the solution to the buffeting problem on long-span bridges, which will involve the direct representation of the sources of uncertainty through statistical descriptors, concentrated in both the aerodynamic input and selected structural parameters. Comparisons will be pursued from data and information available to the Principal Investigator. Wind-tunnel experiments will be used to confirm the relevance of the uncertain definition of aerodynamic and aeroelastic force terms. It is worth emphasizing that, whereas the collapse due to flutter can be re-interpreted from a probabilistic point of view as a reliability problem (i.e., a condition that needs to be avoided statistically), buffeting cannot be exclusively associated with a unique safety index but is related to both failure and serviceability conditions