Dynamic assessment of jointed rock slope stability: FLAC modelling and constitutive model comparisons

This paper presents a dynamic stability analysis of jointed rock masses subjected to seismic loading using the FLAC finite volume method. Three constitutive models—Mohr-Coulomb, Hoek-Brown, and Bilinear Strain-Softening/Hardening Ubiquitous-Joint (SUBI)—were evaluated for their ability to simulate seismic responses in rock slopes. Ground motion data was derived from the Tokachi-Oki earthquake, and dynamic material properties were modelled based on field data and geotechnical testing. The study found that the SUBI model effectively captures strain-softening behaviour and jointed rock mass deformation under seismic conditions, offering more realistic displacement profiles compared to simpler models like Mohr-Coulomb and Hoek-Brown. This work highlights the importance of considering joint strength degradation in seismic slope stability assessments, informing future engineering practices for infrastructure design in seismically active regions.