武汉某超高层建筑对台湾花莲6.9级地震的结构响应分析

Analysis of the Structural Response of a Super High-rise Building in Wuhan to the Hualian,Taiwan M S6.9 Earthquake

为研究2022年台湾花莲6.9级地震对武汉市某超高层建筑结构的影响,初步分析了该建筑结构4个加速度测点记录的各向PGA放大效应、傅立叶谱及反应谱,分别利用互功率谱法和基于协方差的随机子空间法分别识别结构在频域和时域上的一阶模态。结果表明:结构的峰值加速度随楼层的增高而有显著的放大效应,最大放大倍数达7.322倍;各向傅立叶谱峰值均集中在0.275 Hz和1.171 Hz;加速度响应反应谱远小于该地区Ⅵ度设防地震设计谱;两种方法识别的结构一阶模态频率基本一致,均接近数值分析值。台湾花莲6.9级地震没有对该高层建筑结构造成损伤。

Wuhan city is located at the junction of the Jianghan Fault Depression and the Southeastern Hubei Fold Belt,which is often affected by far-field earthquakes.At 14:00 on September 18,2022,a 6.9-magnitude earthquake occurred in Hualian County,Taiwan Province of China.The structural dynamic response of a super high-rise building to the Hualian earthquake was completely recorded at 4 monitoring points in this building in Wuhan,more than 1000 km away from the epicenter.In order to study the impact of the earthquake on the building structure,the anisotropic PGA amplification effect,the Fourier spectrum and the response spectrum are analyzed.The mutual power spectrum method and the stochastic subspace identification method based on covariance are used respectively to identify the first-order modes of the structure in the frequency domain and the time domain.The results show that the peak acceleration of the structure has a significant amplification effect with the increase of the height of the floor,and the maximum amplification factor is 7.322.The peak value of the Fourier spectrum is concentrated at 0.275 Hz and 1.171 Hz.The response spectrum of acceleration response is much smaller than the design spectrum of theⅥ-degree fortification earthquake in this area.The frequencies of the first-order modes identified by the two methods are generally the same,and are close to the values of numerical simulation.It is believed that the Hualian,Taiwan M S6.9 earthquake did not cause damage to the structure of the case building.