Dynamic Response and Stability Analysis of Slopes with Complex Geological Structures under Seismic Loading

Abstract

A three-dimensional dynamic numerical model of a slope with weak interlayers in southwestern China was established in FLAC3D to study its seismic response and stability. Free-field boundaries and local damping were adopted, and the acceleration, displacement, and stress responses under different input frequencies, peak accelerations, and loading directions were examined. The results show that the slope has a clear elevation amplification effect, with the strongest response at the slope crest. Weak interlayers significantly influence seismic wave propagation, energy dissipation, stress redistribution, and local deformation development. Low-frequency seismic motions are more likely to produce dynamic amplification and reduce slope stability. These results help clarify the coupled effects of elevation, weak structural planes, and seismic frequency, and can provide a reference for the seismic design and stability evaluation of similar slopes.