大型火車站雨棚風(fēng)荷載特性試驗研究
孫建龍
- 摘 要
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孫建龍（中鐵第一勘察設(shè)計院集團(tuán)有限公司，西安 710043）［摘要］對3個大型火車站雨棚進(jìn)行風(fēng)洞測壓試驗，分析結(jié)果表明開放式雨棚受站房影響較大，在不同風(fēng)向下可能形成“上吸下頂”的受力特征，造成局部風(fēng)壓幅值的增加。由于風(fēng)壓分布不均勻和尾流區(qū)范圍大等原因，體量較大的雨棚平均整體風(fēng)吸力系數(shù)在-0.25左右，遠(yuǎn)小于小體量的雨棚，且基底豎向反力的變化范圍也比較小。結(jié)合測壓時程，采用廣義坐標(biāo)合成法計算了雨棚的風(fēng)振響應(yīng)，著重指出由于雨棚整體風(fēng)壓基本上是風(fēng)吸力，因而對應(yīng)最大豎向反力的風(fēng)振系數(shù)可能出現(xiàn)負(fù)值或很高的正值，導(dǎo)致得出的等效靜風(fēng)荷載不合理，此時采用附加風(fēng)振力法可得出更符合實際情況的等效靜風(fēng)荷載。［關(guān)鍵詞］雨棚；風(fēng)洞試驗；廣義坐標(biāo)合成法；風(fēng)振系數(shù)；等效靜風(fēng)荷載；附加風(fēng)振力中圖分類號：TU312+.1 文獻(xiàn)標(biāo)識碼：A 文章編號：1002-848X(2013)04-0088-06Experimental research on wind load characteristics of large railway station canopiesSun Jianlong（China Railway First Survey and Design Institute Group Ltd., Xi′an 710043, China）Abstract: It was demonstrated that the wind pressure on the canopy was affected significantly by the station buildings through wind tunnel tests on three large railway stations. The local negative pressure was strengthened by the positive pressure on the underside of the canopy under different wind directions. The average overall wind suction coefficient of the larger canopy was around -0.25 which is much less than that of the smaller canopy, and change range of the vertical reaction force in the bottom was relatively small, due to the non-uniformity pressure distribution and a large area governed by the wake flow. The wind-induced vibration responses were obtained by the generalized coordinates synthesis method on the basis of the wind pressure time history. It was shown particularly that the wind-induced vibration factor corresponding to the maximum vertical reaction force could be a negative value or a rather high positive value as the overall wind pressure of the canopy is basically a wind suction. These unusual factors accordingly led to unreasonable equivalent static wind load. The additional wind-induced vibration force method was suggested to be applied for deriving the equivalent static wind load in such situation.Keywords: canopy; wind tunnel test; generalized coordinates synthesis method; wind-induced vibration factor; equivalent static wind load; additional wind-induced vibration force作者簡介：孫建龍，碩士，高級工程師，Email:tyysjl03@sina.com。參考文獻(xiàn)［1］陳凱，何連華，符龍彪，等. 武漢火車站站房屋蓋和雨棚風(fēng)洞試驗研究［J］. 建筑結(jié)構(gòu)，2009，39(1): 16-19.［2］金新陽，楊易，盛平，等. 新廣州火車站大跨屋蓋結(jié)構(gòu)風(fēng)荷載風(fēng)洞試驗與數(shù)值模擬［J］. 建筑結(jié)構(gòu)，2009，39(12): 55-58.［3］陳凱，錢基宏. 隨機(jī)振動問題的廣義坐標(biāo)合成法［J］. 計算力學(xué)學(xué)報，2012，29(2):171-177.［4］王國硯. 基于等效風(fēng)振力的結(jié)構(gòu)風(fēng)振內(nèi)力計算［J］. 建筑結(jié)構(gòu)，2004,34(7): 36-38.［5］KAREEM AHSAN, ZHOU YIN. Gust loading factorpast, present and future［J］. Journal of Wind Engineering and Industrial Aerodynamics, 2003,91(12): 1301-1328.［6］田玉基，楊慶山，范重，等. 國家體育場大跨度屋蓋結(jié)構(gòu)風(fēng)振系數(shù)研究［J］. 建筑結(jié)構(gòu)學(xué)報，2007, 28(2): 26-31.［7］陳凱，符龍彪，錢基宏，等. 基于響應(yīng)時程的大跨度空間結(jié)構(gòu)等效靜風(fēng)荷載分析方法［J］. 建筑結(jié)構(gòu)學(xué)報，2012，33(1): 35-42.
