曲面屋頂結構物設計風載重之初探

A preliminary investigation on the Design Wind Loads of Arched Roofs

楊承翰(Cheng-Han Yang)

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(2005年)

https://doi.org/10.6846/TKU.2005.00666

摘要

現代建築中因為美學的考量之下,以曲面屋頂為造型的建築物越來越常出現,且因為特別型態的關係所以其特性通常是較輕且較軟的,因此在承受風力時會有更明顯的感受性,而國內目前的風力規範並沒有關於曲面屋頂詳細的設計風載重;所以研究此類屋頂的設計風載重顯得相當需要。
本文主要是探討曲面屋頂之設計風載重，因此以高雄捷運R17車站為研究對象。論文內容分為兩個部份,分別為(1)使用LRC (Load-Response-Correlation)法計算其屋頂設計風載重並與傳統的設計風載重方法做比較。(2)以POD(Proper Orthogonal Decomposition Method)法研究其屋頂實驗風力的風場特性比較與研究。
　　由本文分析結果得知，整個曲面屋頂受風時皆承受上揚力的作用，且在上風處的風力平均值與RMS值皆會比下風處要大，而屋頂風力歷時平均值受到屋頂支撐圓柱一定程度的影響。在LRC法分析當中，取接近屋頂中央桿件為反應的設計風載重是比較符合經濟性與安全性的設計風載重形式。在POD分析中，發現風場的橫向分佈與文獻相同，但是縱向及整體分佈則有很大的不同，需要近一步的研究。

關鍵字

曲面屋頂 ； LRC法 ； 設計風載重 ； POD法

並列摘要

Domes with large span and grand standing arched roofs are common structural forms in the modern architecture practice to meet both the functional requirement and the aesthetic consideration. This type of structure system tends to be light weighted and relatively flexible, therefore, more wind sensitive than the other large structural systems. The simplified design wind load in the current building wind code is suitable only for small to medium size storage dome. A more sophisticated design wind load procedure is needed for large span dome or arched roof system.
In order to investigate the designed wind loads of arched roofs, this project used a real arched roof system in Kaoshiung as the target structure. A properly scaled pressure model was built and the wind pressure of the roof system was measured in a turbulent boundary layer. The Proper Orthogonal Decomposition Method (POD) was applied to get the insight of the wind load on the roof system. The Load-Response-Correlation Procedure (LRC) was used to evaluate the proper design wind load. The POD results indicate that the wind pressure distribution on the roof’s short axis (in the direction of wind) exhibits characteristics of incident turbulence, separation and reattachment as expected. However, the wind pressure distribution on the roof’s long axis (lateral direction to the wind) does not show clear physical significance. The LRC analysis suggests that the design wind load based on the strength of all members would be too conservative. Using a few selected key structural members as the basis of the LRC procedure would yield a more reasonable design wind load.

並列關鍵字

Arched roofs ； LRC(load-response-correlation)method ； design wind loads ； POD(proper Orthogonal Decomposition Method)

參考文獻

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