某会展中心风洞试验研究
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摘要
通过对某会展中心北侧两个大跨波浪形悬挑屋盖的风洞试验研究,讨论了典型风向下屋盖的平均风压分布,同时对全风向角下屋盖平均风压、脉动风压与极值风压的分布进行了研究,并进一步探讨底部开敞对悬挑屋盖风荷载的影响。试验研究表明:屋盖整体以负压为主,除在迎风向的屋盖悬挑区域外,其他区域风压较小;屋盖局部特殊的体型可能产生"兜风效应",从而显著增大风压;而底部开敞造成的"窄管效应"会显著增大开敞区域的风荷载,同时由于底部开敞减弱了气流的堵塞作用,使屋盖上表面风吸力有所减弱,对下表面风压力影响不大;总体而言,屋盖悬挑端在迎风向的体型系数基本在-1.5至-1.8范围。
Based on the wind tunnel test of two long-span waviness cantilevered roofs on the north of a convention center,the mean wind pressure distribution under typical wind direction is discussed. Moreover,the distribution of mean wind pressure, fluctuating wind pressure and extreme wind pressure under the full wind direction are studied.Furthermore,the effect of open bottom on the wind load of cantilevered roof is discussed. The test results show that the roof is mainly presenting negative pressure, and the wind pressure in other areas is very small except for the cantilevered area of the roof under the windward direction. The special shape of the roof may cause "catch the wind" to increase the wind pressure significantly and the "narrow tube effect" caused by the open bottom will increases the wind load in the open area significantly. Meanwhile,since the open bottom weakens the blockage of the airflow, the wind suction on the upper surface of the roof is weakened, but the wind pressure on the lower surface is not greatly affected.The shape coefficient of the cantilevered area of the roof in the windward direction is approximately in the range of-1.5 to-1.8.
Based on the wind tunnel test of two long-span waviness cantilevered roofs on the north of a convention center,the mean wind pressure distribution under typical wind direction is discussed. Moreover,the distribution of mean wind pressure, fluctuating wind pressure and extreme wind pressure under the full wind direction are studied.Furthermore,the effect of open bottom on the wind load of cantilevered roof is discussed. The test results show that the roof is mainly presenting negative pressure, and the wind pressure in other areas is very small except for the cantilevered area of the roof under the windward direction. The special shape of the roof may cause "catch the wind" to increase the wind pressure significantly and the "narrow tube effect" caused by the open bottom will increases the wind load in the open area significantly. Meanwhile,since the open bottom weakens the blockage of the airflow, the wind suction on the upper surface of the roof is weakened, but the wind pressure on the lower surface is not greatly affected.The shape coefficient of the cantilevered area of the roof in the windward direction is approximately in the range of-1.5 to-1.8.
引文
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[3]董欣,叶继红.大跨度平屋盖表面风荷载体型系数研究[J].土木工程学报,2012,45(4):29-42.
[4]李元齐,胡渭雄,王磊.大跨度空间结构典型形体风压分布风洞试验研究现状[J].空气动力学学报,2010(1):32-38.
[5]GB50009-2012建筑结构荷载规范[S].北京:中国建筑工业出版社,2012.
[6]Davenport A G.Note on the distribution of the largest value of a random function witn application to gust loading[J].Proceedings of the Institution of Civil Enigineers,1964,28(2):187-196.
[7]程志军,楼文娟,孙炳楠,等.屋面风荷载及风致破坏机理[J].建筑结构学报,2000(4):39-47.
[8]方江生,丁洁民,王田友.北大体育馆屋盖的风荷载及周边建筑干扰影响的试验研究[J].空气动力学学报,2007(4):443-448.
[2]李方慧,倪振华,沈世钊.不同地貌下几个典型屋盖的风压特性[J].建筑结构学报,2007(1):119-124.
[3]董欣,叶继红.大跨度平屋盖表面风荷载体型系数研究[J].土木工程学报,2012,45(4):29-42.
[4]李元齐,胡渭雄,王磊.大跨度空间结构典型形体风压分布风洞试验研究现状[J].空气动力学学报,2010(1):32-38.
[5]GB50009-2012建筑结构荷载规范[S].北京:中国建筑工业出版社,2012.
[6]Davenport A G.Note on the distribution of the largest value of a random function witn application to gust loading[J].Proceedings of the Institution of Civil Enigineers,1964,28(2):187-196.
[7]程志军,楼文娟,孙炳楠,等.屋面风荷载及风致破坏机理[J].建筑结构学报,2000(4):39-47.
[8]方江生,丁洁民,王田友.北大体育馆屋盖的风荷载及周边建筑干扰影响的试验研究[J].空气动力学学报,2007(4):443-448.