AUTHOR=Yan Jingru , Zhang Yushan 

TITLE=One dimensional time-domain non-linear site seismic response analysis program integrating two hysteresis models of soil

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 10 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.1058386

DOI=10.3389/feart.2022.1058386

ISSN=2296-6463

ABSTRACT=In the numerical simulation of site seismic responses, traditional equivalent linearization methods typically realized in the frequency domain cannot satisfactorily analyze the high-degree nonlinearity of soil under strong input motions. Therefore, the “true” nonlinear numerical methods performed in the time domain are often utilized in such cases. However, a crucial element of the time-domain nonlinear method, which is the hysteresis model of soil that describes the rule controlling the loading–unloading behavior of soil, has no established guidelines for earthquake engineering. Different researchers presented different models, revealing the epistemic uncertainty related to the dynamic properties of soil. Thus, the time-domain nonlinear method should consider this uncertainty in practice. Therefore, in this study, a one-dimensional (1D) time-domain nonlinear site seismic response analysis program was developed. The developed program was coded using Fortran95 and integrates two kinds of soil hysteresis models (i.e., extended Masing model and dynamic skeleton curve model). In both models, the damping correction was introduced to calibrate the hysteresis loop area toward the damping ratio measured in the dynamic triaxial test or resonant column test. Moreover, the temporospatial finite difference algorithm was used to resolve the 1D nonlinear wave equation, and its precision was demonstrated in comparison with the results of the frequency-domain program for the linear case. Finally, the program was applied to calculate the nonlinear seismic responses of a given site, and the uncertainty influence of the soil hysteresis models was discussed in detail.Finally, the nonlinear seismic response of a specific site was calculated by the proposed program. The findings of the fitting were compared to those of the two popular time-domain nonlinear programs DEEPSOIL (Hashash, V6.1) and CHARSOIL (Streeter et al, 1974). Simultaneously, the Japanese KIK-net strong motion observation station data were applied to validate the reliability of this program.