順風向、橫風向、扭轉向風力的極值特性與組合係數之研究

Investigation on the extreme value characteristics and combination factors of building design wind loads.

王靖蕙(Jing-Huei Wang)

指導教授 ： 鄭啟明

淡江大學/工學院/土木工程學系碩士班/碩士(2014年)

https://doi.org/10.6846/TKU.2014.01041

摘要

作用於高層建築物之風荷載，主要受順風向、橫風向與扭轉向3種不同方向之風力影響。在目前國內規範中的建築物設計風力之載重組合，係指依循風的作用方向計算其所對應的順風向、橫風向與扭轉向設計風力，作為該來風方向之設計風力組合。然而於實際情況，同一來風作用的三個方向風力的最大值，並不一定同時發生，亦表示國內規範中的載重組合可能過於保守，故本文將針對此議題加以探討。

　　本文以國內現行規範定義之B地況逼近流場，以及斷面深寬比為1/5、1/4、1/3、1/2.5、1/2、2/3、1/1、3/2、2/1、2.5/1、3/1、4/1、5/1，高寬比為1、1.5、2、2.5、3、3.5、4、4.5、5、5.5、6、6.5、7之矩柱模型所進行量測建築物表面風壓之風洞實驗數據，做其基底風力係數的統計及機率分佈，並討論其結果。

　　而於文中分析的方式，為計算不同模型的風壓實驗數據的基底風力及其風力係數，再以實場十分鐘為段取各方向風力之極值與發生極值下對應的其他方向之值，接著透過統計特性與各方向風力與及值間的比值之關係的機率分佈，提出建議的風力組合係數，期望未來能運用於載重組合係數之推估及相關研究。

關鍵字

高層建築 ； 風載重組合 ； 風力極值 ； 風洞實驗

並列摘要

Wind loads acting on high-rise buildings can be categorized as alongwind, acrosswind and torsional wind loads. The current Taiwan building wind code stipulates to use the largest alongwind, acrosswind and torsional wind loads together as the building design wind loads. However, the largest value of these three wind loads may not occur simultaneously. In this thesis, wind loads of rectangular shaped building models of various side ratio and aspect ratio, obtained from pressure measurements were used to investigate the correlations among three wind loads. Each set of wind loads were divided into 36-40 10-minutes length records. For each 10-minute record, the largest value of alongwind/ acrosswind/ torsional wind load together with the other two wind loads occurred at the same time were established. The mean values, standard deviations and conditional probability mass functions for the other two wind loads under the condition of one certain extreme wind load were calculated for all cases. The correlations of wind loads under the condition of certain extreme wind load were studied. Based on these conditioned statistical characteristics of winds loads, a simplified combination for design wind loads was proposed.

並列關鍵字

high-rise buildings ； wind load combinations ； wind extreme value ； wind tunnel test

參考文獻

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2-5 J. Counihan, (1973), “ Simulation of an Adiabatic Urban Boundary Layer in a Wind Tunnel ”, Atmospheric Environment, Vol.7﹐pp.673-689.