Analysis of Design Wind Speed Variation above the Gradient Height for Large City Terrain.

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基本資料

Project title

Code/計畫編號

NSC101-2221-E019-052

Translated Name/計畫中文名

都會地況設計風速於梯度高度以上風速變化情形之探討

Project Coordinator/計畫主持人

Jing-Jong Jang

Funding Organization/主管機關

National Science and Technology Council

Co-Investigator(s)/共同執行人

林博雄

Department/Unit

Department of Harbor and River Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=2647536

Year

2012

Start date/計畫起

01-08-2012

Expected Completion/計畫迄

31-07-2013

Bugetid/研究經費

484千元

ResearchField/研究領域

土木水利工程

"近來幾年，隨著現代建築技術的進步和都市經濟發展，世界各大都市超高樓建築林立，如台北101 大樓、日本東京天空樹、中東杜拜的哈里發塔，其建物高度分別達到510m、634m、828m，然而現行風力設計規範所訂定的風速梯度高度最高只到500m。實際上，真實自然風場的風速垂直分佈狀態常與理論和規範假設不同；一般而言，實場風速變化並非在到達梯度高度以後保持均勻，反而是會產生內縮或外張的現象。由於目前國內超高層(>300m)風速剖面相關研究不多，也尚無初步具體結論，因此本計畫將針對此主題深入研究探討，相信研究成果將有助於未來高樓結構耐風安全設計。台灣地區位處於太平洋颱風盛行的地區，夏秋之際常遭受到颱風的侵襲，建築物也常損壞。由於颱風時實際的風速剖面與梯度高度，可能不同於現行規範設定的大都會地況Ａ的500 公尺以上風速等速不再變化；實際上，超高層以及梯度高度以上之風速變化難以預測，因此利用風速壓計算式 q  0.5V 2所得之風力來設計超高樓結構，對結構之安全性與經濟性將有完全不同的影響。本研究結合主持人之土木結構風工程專長與共同主持人之大氣科學專長，首先將利用中央氣象局所屬氣象觀測站之探空氣球觀測資料，取得台灣近年來颱風時期風速資料，利用地面高度3000m 以下的風速觀測資料進行分析，主要針對高度500m ~1000m 的風速剖面進行模擬分析。就本研究初步資料分析，風速剖面分佈在梯度高度以上並非定值，常有的內縮現象，大致上可分為四種情況(標準內縮現象、多點內縮現象、內縮現象不明確、內縮點產生停滯)其中以多點內縮現象最多。台灣現行規範於2007 年剛修定施行，也有參照台灣的地理、氣候等條件，做出修正的 及g Z 值，然而對於超高樓結構仍然未有適合的 及g Z 值，期望經過本計畫研究的成果，可以提供未來超高樓結構的耐風設計規範條文修訂之參考。" "There are many super-tall structures were built in recent years, due to the rapid development of building technology and economic growth. Such as the Taipei 101 (509m)、Tokyo Sky-tree Tower (634m) and the Dubai Burj Khalifa Tower (828m). The wind speed is the most important factor for building wind resist design. ( q  0.5V 2 ) However, the wind speed profile of the current building design code is constant for the height above gradient height which is about 500m. Therefore, it is very important to have the accurate wind speed profile distribution for the safety design of super tall buildings with more than 500 meters. Taiwan is a subtropical island and located at the Pacific Ocean Rim where typhoons occurred frequently and lots of tall buildings and structures were damaged every year. The current Taiwan building code for wind resistant design was revised and published in 2007. The wind pressure qZ  is function of wind speed V(Z) with parameters α and Zg. The wind speed profile coefficients introduction into the current building code for wind resistant design is based on the codes of USA and Japan. Up to today, there are few data or researches about the natural wind filed of Taiwan. Thus, this research will focus on the wind speed profile especially for the characteristic of wind speed profile above gradient height in Taiwan large city area during typhoon. This research will collect the wind speed data from the National Weather Bureau and National Taiwan University. We will study the effect of the gradient height wind speed which is varied with height during typhoon. At last, a wind speed profile model will be proposed and a tall building example will be set up. Structural analysis and simulation will be performed to study the effect of different wind sped profile models. The results and conclusions or suggestions of this research will be helpful for future super tall structure wind resistant design code with revised gradient height effect. It will also be useful for the future building design codes revision and benefit the whole structure engineering society."

Keyword(s)

風速剖面
耐風設計
梯度高度
都會地況
wind speed profile
wind resistant design
gradient height
large city terrain

DSpace CRIS

Analysis of Design Wind Speed Variation above the Gradient Height for Large City Terrain.

基本資料

Description