强风作用下楔形外形超高层建筑横风效应试验研究

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1、文章编号:1000-6869(2011)12-0118-09强风作用下楔形外形超高层建筑横风效应试验研究谢壮宁1，李佳2(1．华南理工大学亚热带建筑科学国家重点实验室，广东广州510641;2．汕头大学土木工程系，广东汕头515063)摘要:对正方形平面沿高度方向逐渐收缩的楔形外形超高层建筑进行同步测压试验，分析不同高度横风向气动荷载功率谱密度、相干特征、结构基底气动弯矩和相应的风振响应，在此基础上进一步考虑切角对结构气动荷载和响应的影响。研究结果表明:采用锥形外形可有效地消减作用于结构上的横风向气动荷载，并在一定条件下消减结构的风振响应;楔形外形可以抑制漩涡脱落的强度，但不

2、能消除结构的漩涡脱落现象，且会升高结构的漩涡脱落频率并进而升高结构的风致响应;在楔形外形的基础上再进行切角处理可以基本消除结构的横风向漩涡脱落现象;经切角处理后，楔形外形结构的横风向风致峰值基底弯矩在结构1阶模态自振周期6.12～14.28s范围内基本保持不变;对于锥度η为2.2%和4.4%的高层建筑，切角处理后其100年重现期的峰值基底弯矩分别比未切角减少31.13%和14.58%。关键词:超高层建筑;楔形;切角;风洞试验;横风效应中图分类号:TU973.213文献标志码:ATU317.1Experimentalresearchoncrosswindeffectontape

3、redsuper-tallbuildingsunderactionofstrongwindXIEZhuangning1，LIJia2(1．StateKeyLaboratoryofSubtropicalBuildingScience，SouthChinaUniversityofTechnology，Guangzhou510641，China;2．DepartmentofCivilEngineering，ShantouUniversity，Shantou515063，China)Abstract:Thewindpressuresonseveralbuildingmodelswhi

4、chhavedifferenttaperratio(η)of2.2%，4.4%，6.6%andonebasicbuildingmodelofsquarecross-sectionweresynchronouslymeasuredandrecordedunderthesimulatedboundarylayersrepresentingtyphoonwindfieldusingthesynchronousmulti-pressurescanningsystem．Thepowerspectrumdensity(PSD)ofthecrosswindaerodynamicforce(

5、AWAF)atdifferentbuildingheightandcoherenceofAWAF，PSDofacrosswindaerodynamicoverturningmomentandwindinducedresponse(WIR)wereanalyzedindetail．BasedontheanalysisresultstheeffectofthemodificationofcornercutonAWAFandWIRwereconsidered．TheresultsshowthatataperedtallbuildingmayreducetheAWAFandWIRun

6、dercertainconditions．However，thetaperingstrategystillcannotdispelthevortexsheddingandmayincreasethesheddingfrequencyofthestructure，leadingtothepossibleincreaseofWIRcomparedwiththebasicbuildingmodelofsquarecross-section．Theresultsalsoshowthatthecombinedstrategyoftaperandcornercutcaneffective

7、lydispelthevortexshedding．Andthewindinducedpeakbasebendingmoment(BBM)ofataperandcornercutbuildingkeepsbasicallyunchangedwhentheperiodofthefundamentalmodeofthestructurerangesfrom6.12sto14.28s．Withcornercuttreatment，peakBBMofthetwotaperedbuildingsofη=2.2%a