大深宽比矩形平面超高层建筑横风向气动基底弯矩谱密度模型  

Cross-wind aerodynamic base bending moment spectral density model for rectangular super tall buildings with large side ratios

作　　者：王敏遥 胡晓琦 谢壮宁[1] 余先锋[1] 黄用军 WANG Minyao;HU Xiaoqi;XIE Zhuangning;YU Xianfeng;HUANG Yongjun(State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510641,China;Shenzhen AUBE Architectural&Engineering Design Consultants Co.,Ltd,Shenzhen 518053,China)

机构地区：[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]深圳市欧博工程设计顾问有限公司,广东深圳518053

出　　处：《建筑结构学报》2023年第11期162-169,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(52078221);广东省现代土木工程技术重点实验室资助项目(2021B1212040003)。

摘　　要：为解决现行荷载规范中可获取的矩形平面超高层建筑横风向气动基底弯矩(CABBM)谱密度的深宽比范围有限,在实际工程中适用性不高等问题,利用高频底座测力天平技术,针对深宽比为0.2~5.0的矩形平面超高层建筑模型,开展了4种地貌粗糙度类别的风洞试验。结果表明:深宽比对CABBM谱的影响较大,当深宽比较小时,CABBM谱呈现单峰状,当深宽比超过2.5后,CABBM谱可能会出现再附峰;湍流度对旋涡脱落产生抑制,导致CABBM谱峰及再附峰变钝。根据试验结果以及CABBM谱特性,采用多参数多变量非线性最小二乘法获取了CABBM均方根系数和无因次谱密度的拟合公式。所提出的CABBM谱模型可较全面地覆盖4种地貌粗糙度类别下不同深宽比矩形平面,且可以对未进行试验的参数进行预测,结果显示拟合公式具有合理性和可靠性。The spectral density of the crosswind aerodynamic base bending moment(CABBM)of the rectangular super tall buildings in the existing loading code is only available within limited side ratios,resulting in a limited application scope for practical engineering.To address this issue,wind tunnel tests were conducted for four types of topographic roughness on a rectangular plan supertall building model with side ratios ranging from 0.2 to 5.0 using high-frequency base force balance technology.The results show that the side ratio has a significant influence on the CABBM spectrum.When the side ratio is small,the CABBM spectrum presents a single peak.When the side ratio exceeds 2.5,the CABBM spectrum may have a reattachment peak.Turbulence inhibits vortex shedding,resulting in blunted CABBM peaks and reattachment peaks.According to the test results and the CABBM spectral characteristics,fitting formulae of the RMS CABBM coefficients and the dimensionless CABBM spectral densities were obtained by using the multi-parameter multivariate nonlinear least square method.The proposed CABBM spectrum can comprehensively cover the rectangular planes with different side ratios under four types of topographic roughness,and they can also predict the conditions that have not been tested.The results confirm the rationality and reliability of the fitting formulae.

关 键 词：高层建筑 风洞试验 横风向基底气动弯矩 功率谱密度 数据拟合 

分 类 号：TU973[建筑科学—结构工程]