针对高层建筑结构周期长、阻尼比小的特点,提出改进的多重随机减量法,结合亚伯拉罕时间域法对此类长周期高层建筑结构的自振频率和阻尼比等动力特征参数进行系统识别.结合利通广场某次强/台风影响时实测到的风致加速度信号,采用改进的多重随机减量法对其自振频率和阻尼比,并与传统随机减量法和随机子空间法识别的结果进行对比.分析结果表明,改进的多重随机减量法具有对此类结构动力特征参数进行辨识的可靠性及高效性.
Combined with Ibrahim time-domain identification method, a modified Multiple Random Decrement Technique (MRDT) is proposed for identifying the dynamic characteristic of tall building structures with long periods and small damping ratios. The field measured wind-induced acceleration response of Litong Plaza under a typhoon effect was used in this paper to demonstrate how the proposed MRT could be specially applied for the identification of damping ratios. The identified results from the proposed methods were also compared with those analyzed results from the traditional RDT and SSI methods for the same wind-induced acceleration signals. The reliability and efficiency for the modified MRDT was finally verified from the compared results for the dynamic characteristic identification of such super tall building with long periods.