Research on adhesion properties of tidal flat soil on metal surface and discrete element simulation

The adhesion property of soil on the metal surface was tested by the orthogonal experiment with 4 factors and 3 levels based on piston pull out method. A regression model of adhesion stress and the factors including moisture content($X_1$), pressing time($X_2$), settling time($X_3$) and separation velocity ($X_4$) was established. The experiment results show that the influence of each factor on adhesion stress is ranked as $X_1\approx X_2\approx X_3>X_4>X_3{X}_4$, and the adhesion stress shows an ‘S’ curve with the increase of separation velocity. The DEM parameters of the soil were calibrated based on the test results, and the contact and disturbance state of soil particles during the test were studied by discrete element method (DEM) using JKR model. The simulation tests show that the maximum adhesion stress occurs when the particles are about to separate from the probe surface, and the soil disturbance state is hierarchical.