- 摘 要
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［摘要］介紹了幾種大跨度屋蓋結(jié)構(gòu)下壓風(fēng)荷載的計算方法，并以某大型體育場屋蓋為例，通過引入峰值因子和位移匹配度判據(jù)，分析了等效荷載作用下位移響應(yīng)值和空間分布的合理性。研究結(jié)果表明，按比例放大的陣風(fēng)荷載因子法和動力放大系數(shù)法，當(dāng)計算基準(zhǔn)值較小時，得出的放大倍數(shù)過高，將導(dǎo)致除等效目標(biāo)之外的響應(yīng)值被高估。采用準(zhǔn)靜態(tài)荷載與均勻分布附加風(fēng)振力的線性疊加方法得出的等效荷載將給出較為合理的位移響應(yīng)值，其中又以結(jié)合LRC方法的等效荷載位移匹配度最高。此外，研究表明若不考慮風(fēng)洞試驗結(jié)果，按體型系數(shù)+0.2在半跨屋蓋上作用均勻風(fēng)荷載，也能給出基本合理、工程上可用的下壓風(fēng)荷載。
［關(guān)鍵詞］大跨度屋蓋結(jié)構(gòu)；陣風(fēng)荷載因子；動力放大系數(shù)；下壓風(fēng)荷載；附加風(fēng)振力
中圖分類號： TU312.1, TU311.3 文獻(xiàn)標(biāo)識碼： A文章編號：1002-848X(2011)11-0131-06
Determination method and a case study of the downward wind load acting on largespan roof
Chen Kai, Fu Longbiao, Qian Jihong, Jin Xinyang(CABR Technology Co., Ltd., China Academy of Building Research, Beijing 100013, China)
Abstract: Taking the large roof of a stadium as an example, some methods to determine the downward wind load of large roofs were demonstrated. By introducing the criteria of the peak factor and the response matching factor, it was investigated that if the response values and distribution under the action of the downward wind loads are reasonable. It was shown that the responses except the equivalent target would be overestimated if the scale factors (such as gust load factor and the dynamic factor) were unreasonably high due to the low reference value. However, the responses were sensible under the action of the wind load obtained by superimposition of the quasi-static wind load and uniform additional wind-induced vibration force. In particular, the downward wind load based on the quasi-static wind load of LRC method gave the best match of the response. Besides, it is suggested that the wind load with a shape factor of +0.2 acting on half of the roof is still practicable download wind load if the wind tunnel results are unreachable.
Keywords: large-span roofs; gust loading factor; dynamic factor; downward wind load; windinduced vibration force
*國家自然科學(xué)基金面上項目(50878202)。
作者簡介：陳凱（1976-），男，博士，副研究員，研究方向：風(fēng)工程與荷載，Email：chenk@pku.org.cn。
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