ISO 12494:2017 建筑结构的大气结冰

标准编号：ISO 12494:2017

中文名称：建筑结构的大气结冰

英文名称：Atmospheric icing of structures

发布日期：2017-03

标准范围

ISO 12494:2017描述了确定本条所列类型结构冰荷载的一般原则。如果本标准或其他标准或建议未直接涵盖特定结构，设计师可以使用本文件的意图。然而，用户有责任仔细考虑该文档对所讨论的结构的适用性。本文件中所有数据的实际使用是基于对结构物位置的某些了解。所使用的信息与相关场地的“正常”结冰量（=冰等级）有关。然而，对于许多地区，没有可用的信息。即使在这种情况下，本文件也会很有用，因为当地气象学家或其他有经验的人应该能够在安全的情况下估计出适当的冰层等级。在结构设计中使用这样的估计值，将比在不考虑冰引起的问题的情况下设计更安全的结构。注意:为一些冰而不是无冰进行设计是非常重要的，那么冰的量是否正确的问题就不那么重要了。特别是，由于暴露面积的增加和阻力系数的增加，风的作用会显著增加。ISO 12494:2017旨在确定以下类型结构的冰质量和冰结构上的风荷载:-桅杆；-塔楼；-天线和天线结构；-电缆、拉线、拉线等。；-索道（缆索铁路）；-滑雪升降机的结构；-暴露于潜在结冰的建筑物或其部分；-输电线路、风力涡轮机等特殊结构类型的塔架。IEC（国际电工委员会）标准涵盖了架空电线上的大气结冰。本文件旨在与ISO 2394结合使用。注:提到了一些典型的结构类型，但设计师也可以考虑其他类型的结构，考虑哪种类型的结构对不可预见的冰敏感，然后采取行动。此外，在许多情况下，只有部分结构的冰荷载设计，因为它们比整个结构更容易受到不可预见的冰的影响。即使电气架空线路包含在IEC标准中，如果设计师愿意，他们也可以将本文件用于架空线路（IEC标准未包含）的桅杆结构。

ISO 12494:2017 describes the general principles of determining ice load on structures of the types listed in this clause.In cases where a certain structure is not directly covered by this or another standard or recommendation, designers can use the intentions of this document. However, it is the user's responsibility to carefully consider the applicability of this document to the structure in question.The practical use of all data in this document is based upon certain knowledge of the site of the structure. Information about the degree of "normal" icing amounts (= ice classes) for the site in question is used. For many areas, however, no information is available.Even in such cases, this document can be useful because local meteorologists or other experienced persons should be able to, on the safe side, estimate a proper ice class. Using such an estimate in the structural design will result in a much safer structure than designing without any considerations for problems due to ice.CAUTION It is extremely important to design for some ice instead of no ice, and then the question of whether the amount of ice was correct is of less importance. In particular, the action of wind can be increased considerably due to both increased exposed area and increased drag coefficient.ISO 12494:2017 is intended for use in determining ice mass and wind load on the iced structure for the following types of structure:- masts;- towers;- antennas and antenna structures;- cables, stays, guy ropes, etc.;- rope ways (cable railways);- structures for ski-lifts;- buildings or parts of them exposed to potential icing;- towers for special types of construction such as transmission lines, wind turbines, etc.Atmospheric icing on electrical overhead lines is covered by IEC (International Electrotechnical Commission) standards.This document is intended to be used in conjunction with ISO 2394.NOTE Some typical types of structure are mentioned, but other types can also be considered by designers by thinking in terms of which type of structure is sensitive to unforeseen ice, and act thereafter.Also, in many cases, only parts of structures are to be designed for ice loads because they are more vulnerable to unforeseen ice than is the whole structure.Even if electrical overhead lines are covered by IEC standards, designers can use this document for the mast structures to overhead lines (which are not covered by IEC standards) if they so wish.

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