Abstract: The abandoned rare earth tailings piles are characterized by an anisotropic， structurally disordered， weakly cemented or non-cemented special geological body. The infiltration and failure modes are significantly different from the general soil slopes in extreme rainfall conditions. It is easy to produce local collapse or landslide hazard. Two sets of indoor abandoned rare earth tailings pile models with or without top platforms were constructed， and the pore water pressure， water content， internal and external drainage speed under the same rainfall conditions of the models are tested. Besides that， numerical simulations were carried out to study the failure mode and rainfall infiltration law. The study results show that:①The model of the abandoned rare earth tailings pile with or without the top platform has different response to pore water pressure， water content and drainage speed. The three values of model B （with top platform） are larger than the ones of model A （without top platform）， and its response is also more sensitive. ②The top platform leads to a large difference in the failure mode of the abandoned rare earth tailings model. The failure mode of the model A is relatively simple and the damage is small， only the slope angle produces shallow sliding damage， while the model B occurs at the foot of the slope. The obvious shallow sliding failure is accompanied by cracks in the upper part of the slope failure area. As the test progresses， the fracture further merges with the shallow damage area of the slope foot， and the slope surface goes down from bottom to top. The collapse is destroyed， and the model B is more prone to slope damage. The numerical simulation results are consistent with the model test results. The above study results can provide reliable reference for similar tests and effective prevention and control of local collapse and landslide of abandoned rare earth tailings.

Key words: Waste rare earth tailings heap, Rainfall infiltration, Shallow slide, Collapse damage, Saturation line