Conditionally Simulated Spatial Non-Stationary Earthquake Accelerograms Using Wavelet Packets

ABSTRACT

For regional hazard analysis or engineering applications, it is necessary to simulate a group of correlated ground motions containing information from given recordings. A new method is presented to conditionally generate ground motions at unobserved points using actual recordings in this localized region. This method is based on an extension of the traditional conditional simulation using a wavelet packet. Utilizing the advantages of wavelet-packet transformation, the time and frequency characteristics of ground motions are effectively identified. Besides by decomposing the signal into non-overlapping sub-frequency bands, it is possible to conditionally simulating stationary, space-time, and Gaussian random fields. These simulated motions are consistent with the actual recordings in terms of temporal variations in the frequency domain and its design spectrum, and their coherence functions satisfy the target coherence values. Two numerical examples have been provided to illustrate the capability of the proposed method: the simulation of ensembles of earthquake accelerograms using actual recordings and blind tests in SMART-1 array.

KEYWORDS:

• Conditional simulation
• non-stationary multi-point ground motions
• multivariate linear prediction
• wavelet-packet transform
• response spectrum
• coherency function

Acknowledgments

The data were provided by Pacific Earthquake Engineering Research Center (PEER) and sincerely appreciated.

Disclosure Statement

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.

Additional information

Funding

This work is partly supported by Helongjiang Provincial Natural Science Foundation of China [grant number: LH2022E120].