Full-scale measurements of mode coupling vibrations during super typhoons on a rectangular supertall building with limited sensors

• Published in: Journal of Building Engineering Vol. 85; p. 108658
• Main Authors: Li, Feiqiang, Xie, Zhuangning, Zhang, Lele, Wang, Fei, Shi, Biqing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.05.2024
• Subjects: Field measurement; Structural dynamic property; Super typhoon; Supertall building; Underdetermined blind source separation; Field measurement; Underdetermined blind source separation; Supertall building; Super typhoon; Structural dynamic property
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2024.108658

Towards a complete and accurate assessment of the model parameters (i.e., frequency, damping ratio, and mode shape) of supertall buildings, this study proposes a new modal identification method named SCA-MBSDA based on the framework of sparse component analysis (SCA) and modified Bayesian spectral density approach (MBSDA). The feasibility and uncertainty of the SCA-MBSDA method are analyzed in an underdetermined case using a three-degree-of-freedom frame structure via numerical simulations. Through measurements from a wireless biaxial ultra-low frequency accelerometer atop the building, the variations in the first three modal parameters of a 125 m high rectangular supertall building with significant multi-mode coupling vibrations (maximum accelerations >15 cm/s2) are illustrated during typhoons Hato and Mangkhut. The results demonstrate the high effectiveness of the SCA-MBSDA method in identifying time-varying structural frequencies and mode shapes. During super typhoon conditions, the third mode of the monitored building exhibits a significant decrease in natural frequency and modal stiffness, with reduced rates of 9 % and 17 %, respectively. The averages of the first three mode directions obtained from the measurements agree well with the values obtained from the finite element model (FEM). This paper aims to provide a feasible identification method to enhance the understanding of the changes in the first three modal properties of supertall buildings during typhoons. •A new modal identification method named SCA-MBSDA is proposed with limited sensors.•The effectiveness and accuracy of the proposed method are verified by numerical simulation.•The multi-mode coupling vibrations of a rectangular supertall building during two super typhoons are clarified.•The structural first three mode properties are discussed in detail.