Three-dimensional uplift simulation of anchor plates in sand using material point method

There are complex anchor-soil interactions in the uplift process of the anchor plate, and it is of great significance to master the deformation mechanism and displacement distribution of the soil to predict the uplift bearing capacity and optimize the design. Based on the three-dimensional material point method (MPM) to simulate the uplift of the anchor plate, the uplift failure mechanism under different embedment depth ratios is explored, and the influences of soil compactness, diameter and embedment depth ratio of the anchor plate on the peak bearing capacity are analyzed using limit equilibrium method. The results show that the limit embedment depth ratio is mainly affected by the nature of the soil, but less affected by the diameter. When the embedment depth ratio is less than the critical one, the soil exhibits shallow embedment failure, and the failure surface extends to the surface. Its shape is truncated cone-shaped in loose sand and curved in dense sand. When the embedment depth ratio is greater than the critical one, the damage surface in the soil is bulb-shaped and does not extend to the surface. When the uplift displacement is large, the soil above the anchor plate appears to flow around. When the embedment depth ratio remains unchanged, the larger the plate diameter, the greater the ultimate bearing capacity, and the smaller the uplift bearing capacity coefficient. Considering the softening effects, the load-displacement response in the uplift process of loose sand and dense sand is different. The ultimate bearing capacity of the dense sand is greater than that of the loose sand, and the difference between them increases with the increase of the embedment depth ratio.