We develop a time-domain analysis framework that couples the indirect boundary element method (IBEM) with the discrete element method (DEM) to investigate the dynamic response patterns and failure mechanisms of rock slopes subjected to near-fault ground motions. This framework enables a nonlinear dynamic simulation approach for near-fault slope systems

capturing the discontinuous deformation characteristics of rock and soil masses. Firstly

we construct a high-precision numerical model of the kilometer-scale

semi-infinite near-fault seismic wavefield using IBEM. Subsequently

based on Green’s function theory and the IBEM solution of the wavefield

we derive an explicit formulation of the equivalent seismic loads on the boundaries of the DEM computational domain. This enables cross-scale energy transfer within the IBEM-DEM coupled system. Finally

the DEM resolves the nonlinear dynamic response of meter-scale rock slopes

yielding a multi-scale nonlinear seismic simulation framework that spans from kilometer-scale faults to meter-scale slopes. Numerical simulations combined with dynamic monitoring results demonstrate that the IBEM-DEM coupling algorithm can accurately capture the dispersion characteristics and energy attenuation patterns of near-field seismic wave propagation. Under near-fault seismic loading

progressive shear failure first occurs within weak interlayers

leading to strength degradation

the formation of through-going rupture surfaces

and subsequent accelerated instability of the sliding mass along the shear plane. This process induces significant displacement and velocity responses

ultimately forming a typical debris accumulation at the slope toe. The surface velocity of the sliding mass is markedly greater than that at the base

with the mean surface velocity reaching 3.6 times that of the base

and peak X- and Z-direction velocity components of 4.98 m/s and 5.92 m/s

respectively

exhibiting a pronounced surface-acceleration effect. The monitoring points of the sliding mass exhibit maximum displacements of up to 41 m in the X-direction and 35 m in the Z-direction from the initial slope surface to the final accumulation position

with the displacement-time history showing a distinct step-like growth pattern

indicative of abrupt sliding behavior during the alternating transformation of kinetic and potential energy. The IBEM-DEM coupled method developed in this study reconstructs the full evolutionary sequence from rock mass rupture to landslide formation

providing an innovative analytical framework for the dynamic failure analysis of landslides induced by near-fault ground motions

as well as theoretical and technical support for identifying landslide mechanisms and mitigating seismic hazards in complex geological settings.