Investigation of Thunderstorm Winds with Respect to Wind Load Design Criteria and the Safety of Structures

目前的估算方法 非飓风设计风速 美国的一些地区没有 分辨风 源于大规模 减压系统和 小而强的雷暴 这两种不同的气象 现象有单独的统计 分布，基于 第一阶段的结果，不应该是 使用单个（混合）处理 分布，目前 案子 在第一阶段研究中， 似乎有很多 在美国， 雷暴大风主宰了 极端风气候学（ 回归周期与 常规结构设计）和 传统的方法 低估了设计风 过于狭隘地模拟风 方向性分布 以来 雷暴与大型雷暴不同， 尺度温带风 详细的风结构，风暴 持续时间、频率和 方向性，这些差异 可能会产生重要的影响 关于未来编纂 设计风，安全 结构和风洞试验 在美国 第二阶段的目标 研究是为了评估 治疗的重要性和优点 雷暴阵风锋面风 独立风荷载 活动 综合研究 计划包括三项基本任务： (1)开发风力工程模型 的时空 雷暴特征 阵风锋;（2）分析 雷暴与非雷暴 风速风向统计 在选定的地点;（3）评价 雷暴对 几个结构响应 结构的类别。 工作 可能具有全国性的意义 如果成功的话， 未来风荷载设计准则 美国等 有雷暴的国家 极端的重要贡献者 风的频率

Current methods for estimating design wind speeds in non-hurricane regions of the United States do not distinguish between winds originating from large-scale extratropical pressure systems and small but intense thunderstorms. These two different meteorological phenomena have separate statistical distributions and, based on the Phase I results, should not be handled using a single (mixed) distribution, as is currently the case. From the Phase I study, it appears that there may be many sites in the United States where thunderstorm winds dominate the extreme wind climatology (for the return periods relevant to conventional structural design) and that the traditional approach tends to underestimate the design winds and too narrowly models the wind directionality distribution. Since thunderstorms differ from large- scale extratropical winds in the details of wind structure, storm duration, frequency, and directionality, these differences could have an important influence on the future codification of design winds, the safety of structures, and wind tunnel testing in the United States. The objective of the Phase II research is to evaluate the importance and merits of treating thunderstorm gust front winds as a separate and distinct wind loading event. The integrated research plan includes three basic tasks: (1) develop wind engineering models of the spatial and temporal characteristics of thunderstorm gust fronts; (2) analysis of thunderstorm and non-thunderstorm windspeed and direction statistics at selected sites; and (3) evaluate the effects of thunderstorms on structural response for several categories of structures. The work could have nationwide significance and, if successful, influence future wind load design criteria in the United States and other countries where thunderstorms are important contributors to extreme wind frequencies.