低矮建筑不同形式屋面局域破坏所致风载特性试验研究  

Experimental study on wind load characteristics induced by local failure on different roofs of low-rise building

作　　者：蒋姝 戴益民 袁养金[1,2] 宋思吉 JIANG Shu;DAI Yimin;YUAN Yangjin;SONG Siji(Hunan Provincial Key Laboratory of Structural Wind and Vibration Control,Xiangtan 411201,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]结构抗风与振动控制湖南省重点实验室,湖南湘潭411201 [2]湖南科技大学土木工程学院,湖南湘潭411201

出　　处：《自然灾害学报》2021年第6期115-125,共11页Journal of Natural Disasters

基　　金：国家自然科学基金项目(51578237,52178478);湖南省研究生学位教育改革重点项目(2019JGZD063);湘教通[2018]436号1017号,湖南省教育厅科学研究重点项目(19A168)。

摘　　要：针对低矮建筑屋面易损区局部风毁进行风洞试验,对比研究了0°与18.4°坡角屋面局域风毁所致内外平均风压系数特性、内外压脉动特性以及屋面净风压极值变化规律。结果表明:两种屋面的开孔所致平均内压系数均随开孔率增大而增大,但平屋面开孔所致平均内压系数受来流风向及开孔形状的影响更大,明显大于坡屋面开孔情况;平屋面开孔脉动内压放大效应明显高于坡屋面开孔;坡屋面开孔所致内压的Helmholtz和旋涡脱落频率均低于平屋面开孔,屋面开孔所致内压的Helmholtz频率基本不受开孔位置及风向角变化的影响。Through the wind tunnel test on the local failure in vulnerable areas of low-rise building roofs,the comparable study on the characteristics of mean and fluctuating wind pressure inside and outside the roof and the variation of extreme net wind pressure on the roof were carried out.The results show that the influence of wind angle and opening shape on mean internal pressure caused by flat roof opening is obviously greater than that of gable slope roof,and the mean internal pressure of the two kinds of roofs increases with the increasing opening ratio.The maximum fluctuating internal pressure is found when the corner openings of the two roofs are facing the wind.The magnification effect of fluctuating internal pressure on flat roof opening is obviously greater than that on gable slope roof opening.The Helmholtz and vortex shedding frequencies of internal pressure caused by slope roof openings are lower than those of flat roof openings,and the Helmholtz frequencies of internal pressure induced by openings on the two kinds of roofs hardly change with the variation of opening position and wind directions.The extreme value of net wind pressure along the cross wind direction of the two roofs is basically unchanged,and the extreme value of net wind pressure on the windward side is slightly larger than that on the leeward side of the roof,while the extreme value of net wind pressure along the downwind roof is basically decreasing.

关 键 词：低矮建筑 屋面开孔 风洞试验 风致内压 净风压极值 

分 类 号：TU24[建筑科学—建筑设计及理论] TU3