良态风和台风下的上海中心大厦动力参数分析

Dynamic Analysis of Parameters of Shanghai Tower in Normal Wind and Typhoon

摘要:

基于2016—2017年日常监测数据和2018年7月台风“安比”登陆时的监测数据，对上海中心大厦动力参数变化规律进行对比分析和研究.利用包络随机减量法，分析低振幅与高振幅下的结构一阶自振频率与振幅、一阶阻尼比与振幅的变化规律.结果表明,良态风作用下，结构振幅低，一阶自振频率随振幅的增加而减小，一阶阻尼比随振幅的增加而缓慢增加；台风作用下，一阶自振频率与振幅仍呈线性关系，由于阻尼器影响，一阶阻尼比与振幅的变化呈现非线性；设计阶段，上海中心大厦在正常使用条件下及台风作用下阻尼比分别取0.3%~1.0%和4.0%较为合理.

Abstract:

Based on the daily monitoring data from 2016 to 2017 and the data of typhoon “Ampil” in July 2018, the dynamic characteristics of Shanghai Tower were analyzed. The fundamental natural frequencies and damping ratios of Shanghai Tower were calculated by using the envelope random reduction method. The variations of dynamic parameters with vibration amplitude at low and high amplitudes were analyzed, respectively. The results show that the fundamental natural frequency of the structure decreases with the increase of vibration amplitude, and the fundamental damping ratio slightly increases with the increase of vibration amplitude. Furthermore, in typhoon “Ampil”, the fundamental natural frequency is still linear with vibration amplitude, and the relationship of the fundamental damping ratio and amplitude is nonlinear because of the influence of the damper. At the design stage, it is reasonable to set the structural damping ratio under normal service conditions and typhoon as 0.3% to 1.0% and 4%, respectively.