A novel framework for parameterization and simulation of near-fault velocity-pulses

Structures subjected to velocity-pulses have to dissipate a larger amount of energy within a shorter time, thereby imposing elevated structural demands and heightening the risk of earthquake-induced collapse. Effective parameterization for identifying potential pulses and simulation for spectrum-compatible pulse-like ground motions are pivotal in structural response analysis. The present study aims to propose a novel framework for the parameterization and simulation of spectrum-compatible velocity-pulses. Initially, a novel velocity‑pulse parameterization algorithm is proposed based on a signal-only objective function, eliminating the need for any filtering techniques or preset pulse model parameters. The comprehensive comparison with two typical methods illustrates that the potential pulses extracted by the proposed method are much closer to the original seismic record, both in the velocity time-history and spectrum. Subsequently, XGBoost-based prediction model for pulse period has been presented, which can be utilized to calculate the site-specific target spectrum for the velocity-pulses. The challenge of maintaining dominant pulses while generating spectrum-compatible ground motions adds complexity to this research. To address this, an innovative approach for simulating spectrum-compatible velocity-pulses is proposed through modifying wavelet coefficients of seed record based on the Gaussian function, and the reliability of the proposed simulation approach is demonstrated through several case studies.