Discussion on "Seismic reliability assessment of earth rockfill dam slopes considering strain softening of rockfill based on generalized probability density evolution method" by R. Pang et al. [Soil Dyn Earthq Eng 107 (2018) 96 107]
Abstract This discussion is based on the paper by Pang et al. [1] In this paper, the authors made important contribution to the understanding of seismic stability of rockfill dams by considering the effects of strain softening of materials and the uncertainty of earthquake excitations. It is well known that granular materials may exhibit significant softening behaviour depending on the magnitudes of confining stresses and shear strains, and such behaviour leads to a progressive propagation of failure zones in the relevant rockfill structure. This discussion presents some comments on the definition of safety factor, the representativeness of stochastic ground motions and the range of shear strains used in the reported dynamic response analyses, implying that some further clarification and or improvement may be needed.