Prediction of liquefaction time based on time-frequency distribution of seismic records

By considering the characteristics of the time-frequency curve of ground acceleration at liquefaction sites, this research introduces the concept of a step function, defines an error function, and establishes criteria for identifying site liquefaction time. A novel method for site liquefaction time identification is proposed. One-dimensional and two-dimensional non-linear site response analysis models are established, and real liquefaction cases are studied to compare and analyze the two methods. The results demonstrate that the error function effectively identifies the moments when the frequency of the time-frequency curve of ground acceleration undergoes rapid changes, enabling the identification of site liquefaction time.