Traction characteristics and failure mechanisms of deep-sea ultra-soft sediment under grouser shear

Traction performance is a critical factor governing the robust operation of deep-sea tracked mining vehicles on ultra-soft sediments. However, classic terramechanics models, such as the Bekker and Wong formulas, systematically underestimate traction capabilities as they neglect the complex soil accumulation and geometric effects induced by curved grousers. To address this, an improved analytical model based on Coulomb's passive earth pressure theory was developed, incorporating a correction factor ( k ) to account for grouser curvature and soil accumulation. A biomimetic grouser inspired by buffalo hoof morphology was designed and experimentally tested to validate the model. Results demonstrate that optimizing the dimensionless straight segment length ( L *) and curvature radius ( R *) enhances traction by 3–6 % compared to traditional flat grousers. A response surface analysis identified the optimal configuration ( L = 50 mm, R = 200 mm) and revealed that L plays a more dominant role than R . Crucially, comparative analyses confirm that the proposed model significantly outperforms the Bekker model, reducing the prediction error from 12.55 % (Bekker model) to just 0.75 %. These findings provide precise quantitative guidance for optimizing the maneuverability of next-generation deep-sea mining vehicles.