Failure mode and dynamic response of loess slopes with tectonic joints under seismic action

The tectonic joints in loess have an important controlling effect on the stability of loess slopes, which are an essential factor in the study of loess slope seismic hazards. Based on the investigation of tectonic joints in Yuncheng, Shanxi Province, the failure laws of loess slopes with different joint configurations were investigated via the discrete element method. The results indicate that under seismic action, the failure mode of joint loess slope is mostly characterized by cracks expanding along the joint at both ends first; when the joints are penetrated, the sliding body slides along the joint surface. The effect of joint occurrence on slope stability is slope damage is more severe when the angle of the down-dip joint is 15°–60°; the slope of the anti-dip joint is relatively stable; slope damage susceptibility increases when the joint and slope surface dip directions are in alignment. X-shaped conjugate joints accelerate the damage process of slopes, and the peak ground acceleration amplification factor of this type of slope is higher overall than that of single-joint slopes. The results of the study provide a relevant scientific basis for the seismic design of slopes containing tectonic joints in the Loess Plateau region.