Comparative study of decoupled- and coupled-based predictive models for seismically-induced slope displacements during shallow crustal earthquakes.

Various predictive models for the seismically-induced displacement (D) of flexible slopes during shallow crustal earthquakes are available in the literature, but the model-to-model difference of predictions remains unclear. This paper conducts a comprehensive comparative study of ten representative D models based on scenario- and probabilistic-based displacement analyses. Explicit expressions are provided to implement the probabilistic displacement hazard approach, in which copula theory is utilized for deriving the joint occurrence probability of ground-motion parameters. A total of 6048 displacement hazard analyses are performed considering different earthquake and slope scenarios. It is found that the model-to-model difference generally becomes larger with increasing the natural period (T s) of a sliding mass, whereas the within-type difference among different coupled models is notably smaller than that of the decoupled models. The coupled-type models generally result in smaller total variability of D as compared to the decoupled-type models. Meanwhile, the coupled models tend to, on average, yield larger (or smaller) hazard-consistent D than the decoupled models for T s larger (or smaller) than an intersection period T s,inter , though the difference between the two model types diminishes as T s approaches zero. The effects of ground-motion model selection and ground-motion parameter correlation are also discussed. This study could hopefully provide insights into the displacement model selection for the seismic slope performance assessment and regional landslide hazard mapping. • Comparative studies of ten slope displacement models are conducted. • Copula-assisted probabilistic displacement hazard procedures are presented. • Models yielding lower- and upper-bound displacement hazards are identified. • Relative difference between decoupled and coupled predictions is closely related to T s. • Within-type difference among coupled models is smaller compared to decoupled models. [ABSTRACT FROM AUTHOR]