Large-Scale Test Model of the Progressive Deformation and Failure of Cracked Soil Slopes

A large-scale test bed (LWH=6 m×3 m×2.8 m) instrumented with various sensors is used to examine the effects of rainfall infiltration and evaporation on the deformation and failure of cracked soil slopes, taking the Anhui area along the Yangtze River as a field example. The results indicate that (1) during rainfall, the soil around the shallow shrinkage fissures attains transient saturation, and the attendant decrease of matric suction is the primary cause of the shallow slope failure; (2) slope deformation continues during post-rainfall evaporation; (3) if a period of evaporation is followed by heavy rainfall, soil creep is concentrated near the deepest cracks, and two zones of steep gradients in pore pressure form at the crest and toe of the slope. Finally, a saturated zone forms near each crack base and gradually enlarges, eventually forming a continuous saturated layer that induces the slope instability or failure.