锥度化方形截面高层建筑的气动力特性  

Aerodynamic Characteristics of Tapered Tall Buildings with Square Section

作　　者：张正维[1,2] 全涌[1] 顾明[1] 熊勇[3] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]奥雅纳工程咨询(上海)有限公司,上海200031 [3]四川公路桥梁建设集团有限公司勘察设计分公司,四川成都610042

出　　处：《西南交通大学学报》2014年第5期772-778,共7页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(50878159;90715040)

摘　　要：用高频测力天平技术,对不同锥度比的方形截面高层建筑进行了风洞试验,分析了锥度比、湍流度和风向角对方形截面高层建筑基底弯(扭)矩系数、基底弯(扭)矩谱密度与基底弯(扭)矩间相关性的影响.试验结果表明:锥度化措施能减小方形截面高层建筑基底弯(扭)矩系数幅值25%以上,但不能改变基底气动力随风向角的变化规律;锥度化措施能减小所有折减频率范围内顺风向与扭转向基底弯矩谱,但只能减小低频区域横风向基底弯矩谱和谱峰高度,却增大旋涡脱落频率和高频区横风向基底弯矩谱;随来流湍流度增大,锥度化措施对风荷载的抑制效果减弱;折减频率在0.10到0.15时,锥度化措施能增大横风向基底弯矩与基底扭矩间的相关性.Square tall buildings with different taper ratios were tested using the high frequency force balance （HFFB） technique in two different simulated wind fields. The effects of taper ratio, turbulence intensity and wind direction on aerodynamic base moment and torque coefficients, the power spectrum densities （PSD） of along- and across-wind base moments and torques, and the correlation between base moment and torque were analyzed systematically. The test results indicate that tapering of square tall buildings can reduce the amplitudes of the aerodynamic base moment and torque coefficients by 25% or more, but can not change the law of aerodynamic wind loads varying with wind directions. The tapering measure can reduce the PSDs of along-wind base moment and torque within all the reduced frequencies, but it can only reduce the spectral peak value of the PSD of across-wind base moment in low frequency region, and increase the frequency of the vortex shedding and the PSD value in high frequency region. With the turbulence intensity increasing, the effect of the tapering measure becomes weak. The coherence between across-wind base moment and torque is increased by the tapering measure when the reduced frequency is between 0. 10 and 0. 15.

关 键 词：高层建筑 锥度化措施 气动措施 高频测力天平 风洞试验 

分 类 号：TU375.4[建筑科学—结构工程]