Evaluation of applicability of energy thresholds for prediction of non-rigid slopes

Traditional slope stability analyses rely on acceleration-based models that often miss failure initiation in deformable slopes under seismic loading. This study evaluates an energy-threshold approach (EQ*) to predict failure onset. Shaking-table tests were performed on dry sand slopes with inclinations of 13°–20° and sand layer thicknesses of 0–6.5 cm. Results showed a linear relationship between input vibration energy (EEQ) and horizontal displacement (Δr) of a rigid surface block, largely independent of excitation frequency. For a 15° slope with a 6.5-cm sand layer, the regression was Δr = 0.49EEQ + 0.04 (R² > 0.9). A critical energy threshold (EQ* ≈ 1.0 J) marked the onset of sustained failure motion. Validation using documented slope failures confirmed the approach’s predictive capability. Compared with acceleration-based methods, the energy criterion is frequency independent and sensitive to soil conditions, supporting its integration into seismic hazard assessment and design frameworks for more reliable landslide risk mitigation applications.