First World Congress of International Consortium on Geo-disaster Reduction (1st ICGdR World Congress)

Fracture-zone softening can strongly influence slope failure under sequential rainfall and seismic loading. However, the progressive linkage between crest cracking, localized fracture-zone deformation, and sliding-surface formation remains poorly understood. A large-scale shaking-table test was conducted on a fracture-zone-controlled slope subjected to an earthquake–rainfall–earthquake loading sequence. The dry model was first subjected to the Wolong ground-motion record at 0.2g and 0.4g, followed by artificial rainfall and subsequent three-component shaking from 0.2g to 1.0g. Surface observations and particle image velocimetry revealed a progressive failure process. Crest cracks initiated after rainfall, propagated downslope with increasing excitation, and gradually connected with localized deformation along the fracture zone. After the 1.0g excitation, the sliding surface became fully connected, resulting in overall slope failure. These results indicate that rainfall-induced fracture-zone softening increased the susceptibility of the slope to localized deformation and controlled both the progressive failure path and the final sliding mode under subsequent strong shaking.

fracture-zone-controlled slope,rainfall-induced softening,shaking-table test,deformation localization,progressive failure