Damage characteristics extraction and identification of the crane-wharf structure in liquefiable stratum based on Hilbert-Huang transform.

• A centrifuge experiment of the crane-wharf structure in liquefiable stratum is implemented. • The damage state of the crane-wharf structure is analysed by calibrated 3D numerical model. • The framework for structural damage characteristics extraction and identification is proposed. The damage state of the crane-wharf structure is difficult to describe quantitatively in earthquake, which brings great challenges to its emergency rescue and post-earthquake repair. At present, the criterion for evaluating the crane-wharf structure damage reflect a certain section or point, such as bending moment, axial force, displacement, stress, strain curvature, etc., which cannot reflect the overall performance and can be easily obtained. In addition, in the current popular performance-based seismic design concepts, the definition of damage degree is an indispensable part, which shows that the extraction and identification of damage characteristics is imminent. Therefore, on the basis of results of centrifuge experiment that have been carried out under different damage conditions, the basic damage law of the crane-wharf structure in liquefiable stratum is analysed first in the study, and it is clear that the existing means cannot distinguish the damage degree in detail. Furthermore, the proven numerical modelling techniques and the Hilbert-Huang transform theory are applied to extract and identify damage characteristics of the crane-wharf structure, Finally, the corresponding damage index is constructed and damage criterion are developed, which provided a reference for damage evaluation of similar structures in liquefiable stratum. [ABSTRACT FROM AUTHOR]