台风作用下深圳新世界中心风致响应实测与风洞试验研究

Field measurements and wind tunnel experimental investigations of typhoon effects on Shenzhen New World Center

依据近10年来监测到的5次强台风过境期间深圳新世界中心的实测响应数据,分析了该建筑结构在台风影响下的响应特点和模态参数变化特性,并将实测结果与粗糙度指数α分别为0.22,0.30和0.35地形下的风洞试验结果进行了比较。结果表明:历次台风影响下实测建筑达到最大振幅附近时均表现为明显的横风向振动,且最大振动方向均为南北方向;实测最大峰值加速度为17.28 cm/s^(2),满足舒适度要求;台风过境时,建筑结构模态频率表现出明显的振幅依赖性和时变特性,采用“时变”方式描述更加合理,几次台风过程的结构模态频率均是随时间先减小,在最大风速时达到最小值,然后增大并恢复到常态值;结构模态阻尼比在中低振幅区域分布较为离散,随着振幅的增加,阻尼比有所增大,顺风向和横风向的阻尼比最大分别为1.9%和1.2%;实测结果更接近于α为0.35地貌的风洞试验结果,显示C类地貌的风洞试验结果偏于保守。

In this paper,the characteristics of structural response and modal parameters of Shenzhen New World Center(height 238 m)are analyzed based on the field data during five typhoons in the last 10 years.The field results are further compared with the wind tunnel test results when the roughness exponentαis 0.22,0.30 and 0.35 respectively.The field results show that the building exhibits obvious crosswind vibration when reaching its maximum vibration amplitude,and the corresponding vibration is in the north-south direction.The measured maximum acceleration is 17.28 cm/s^(2),which meets the requirement of residential comfort.During the five typhoons,the modal frequencies are shown to be evidently amplitude dependent and time-varying,and it is more reasonable to describe the variation of modal frequency with time than the variation with amplitude.The modal frequency first decreases with time and reaches its minimum at the peak wind speed,and then returns to the normal value.The modal damping ratios tend to be scattered in the middle-and low-amplitude region,and rise slightly with increase in the amplitude.The maximum damping ratios in the alongwind and crosswind directions are 1.9%and 1.2%,respectively.The wind tunnel test results forα=0.35 are in good agreement with the field measured results,indicating that the wind tunnel test results for terrain category C are conservative.