Analysis of Wind Loading Coefficients of Wind Resistant Design Code (II)

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基本資料

Project title

Code/計畫編號

NSC97-2221-E019-020

Translated Name/計畫中文名

耐風設計規範風力計算相關係數研究(II)

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=1685801

Year

2008

Start date/計畫起

01-08-2008

Expected Completion/計畫迄

31-07-2009

Bugetid/研究經費

427千元

ResearchField/研究領域

土木水利工程

台灣四面環海，又位處西太平洋熱帶氣旋盛行之地區，每逢夏、秋兩季便經常遭受颱風之傾襲。國内對風力之研究，部分承襲美國與日本之風力規範，但若要針對台灣複雜的海島型氣候，應仍有許多部分需考量台灣之地理、氣候等條件進而作出修正。因此本計劃將針對颱風來襲時，建築物面臨之風與雨同時作用下之影響。本研究為三年期計畫，第一年已執行的研究計劃是利用可降水量之觀念導出颱風來臨時之飽和空氣密度，以求得隨高度變化之風速壓力與設計風力，再引入陣風反應因子即得建築物之設計風力。再來利用粒子動量方程之原理，模擬各粒徑之雨滴軌跡求出其水平雨速，利用水平雨速及直接降雨強度計算橫埽雨量強度。的自然風場監測數據，收集近年來颱風橫掃臺灣北部所測得到大氣資料之可降水量常年風速資料。接下來的研究方向是對於位處亞熱帶氣候之臺灣地區，尤其是在颱風侵襲時，其溫度、濕度及大氣壓力等特性都不同於上述假設條件的氣候型態，因此對於係數0.0625是否適用於台灣地區，本研究將持續之前的研究進一步探討與確認。再者設計風速壓力計算式中足(Z)(地況係數）為風速剖面a和Zg值的函數，過去因國内無相關本土自然風場資料及相關研究，致現行規範對風速剖面之係數之取捨大致依倨美、日規範，本計劃將取得本土實際自然風場資料，進一步推求適合本國地理特性之風速剖面參數。接下來將蒐集中央氣象局與中華民國空軍，探空氣球實測數據，其次暸解風速剖面參數之意義及影響量，繼而初步運用本土自然風場數據加以分析推求更適用於台灣的a及Zg值，期做為日後規範修訂時之參考。最後將統合前二年研究成果考慮本土特性的空氣密度p值與風速剖面a、Zg 值，以一高樓層範例進行模擬比較分析，探討影響差異程度，提供未來高樓耐風設計分析參考。探討堂灣地區颱風時風力特性，以提供未來結構耐風設計分析及之。相將和颱風之安全可靠度。" "Taiwan is a subtropical island and located at the Pacific Ocean Rim where earthquake and typhoons occurred frequently and lots of building and bridge structures damaged every year. Usually, Typhoon comes with heavy rain in summer. Such as 1996 Herb typhoon and 1997 Winny typhoon. Both typhoons caused billions of economic loss for Taiwan. It is very important for us to design wind resistant structures in addition to predict the location, path and strength of typhoon which will strike Taiwan island in order to reduce properties damage and economic loss or prevent life loss. The current Taiwan building code for wind resistant design was published in 1974, and revised by Prof. Tasi in 1996 and reviewed by Architecture and Building Research Institute in 2004. Basically, it is based on USA’s ANSI/ASCE 7-2002 and Japan’s AIJ-96 building codes. The wind pressure q(Z ) is the function of the values of the wind speed profile α and Zg. The wind speed profile coefficient introduction into the current building code for wind resistant design is based on the codes of USA and Japan. There are no data or researches about the natural wind filed of Taiwan. Thus, this research will study the wind speed profile which approach to the characteristic of geography in Taiwan. This project a 3 years research proposal. First, we will collect the climate data such as: the atmospheric like precipitable water、 temperature、 height、 humidity、atmospheric pressure、 saturation vapor pressure、drop size of raindrops and the terminal velocity of a raindrop of Taiwan from the National Weather Bureau and National Taiwan University 、 Central University and Wind Engineering Research Center of TamKang University. This research will study the wind-driven-rain effect for the air density which is vary with height during typhoon. The horizontal velocity of the raindrop will calculated by the equation of motion of the particles. Using the driven-rain intensity coefficient Cdr(Ih) the driven-rain intensity can be obtained. On the other hand, with reference to wind speed profile we will use the different instrument to sampling、analyze and compare with real data and regression the value to calculate the design wind loading coefficient during typhoon. At last, a tall building example will be set up. Structural analysis and simulation will be performed to study the dynamic behavior of structure by using computer program. The building is subjected to both wind and wind-rain pressure loading. The results and conclusions or suggestions of this research will be helpful for future structure design code revised with wind-rain effect consideration. It will also useful for the future building design code and benefit the whole society."

Keyword(s)

風力係數
風雨效應
空氣密度
風速剖面
Wind Loading Coefficient
Wind-Rain Effect
Air Density
Wind Speed Profile

DSpace CRIS

Analysis of Wind Loading Coefficients of Wind Resistant Design Code (II)

基本資料

Description