SHM-based robustness: a super-tall structure case study

In this paper, the super-tall building of Guangzhou city in China is considered as case study. The region in which this tower stands is exposed to extreme events, such as typhoons and earthquakes. Therefore, the structure was equipped with a long term SHM system and the behavior of the tower upon these extreme events was recorded and analyzed. Several algorithms to assess the damage conditions from output-only measurements of the structure are present in literature. Toward the improvement of the structural robustness, particular attention is herein dedicated to investigated the potentialities offered by the Hilbert-Huang transform method improved by a filtering procedure. Indeed, this method provides the energy distribution of the analyzed signals not only in the frequency domain, but also in the time domain. From the Hilbert spectra is then possible to detect the occurrence in time of the consequences of an extreme event on the structure, such a sudden loss of stiffness. This valuable information would enable to send, in real-time, an alarm about the structural conditions to the responsible persons who could take a suitable decision in order to avoid or limit the catastrophic consequences of a failure. This advantage of the Hilbert spectrum is mostly useful not only in the case of earthquakes, but also upon the occurrence of a vehicle collision with the structure or a nearby explosion.