Study On Rainfall Infiltration Simulation Experiment And Time-space Failure Law Of Ion Type Rare Earth Tailings

In this paper,the ionic rare earth tailing heap is taken as the research object.Firstly,the physical properties of the rare earth are measured to understand the physical properties of the rare earth materials used in the test,such as particle size grading,internal friction angle ?,cohesion c,permeability coefficient and maximum water content,etc.;then,the indoor ionic rare earth tailing is carried out under the conditions of no slope top platform,different rainfall types and different slope angle sizes Rainfall infiltration and damage evolution of ion type rare earth tailings were simulated by rainfall infiltration test.The FLAC3 D software is used to simulate it,which provides a significant contrast and verification for the indoor simulation test of the ion-based rare earth tailings pile.The two-dimensional area and three-dimensional volume of the failure area and the change rate in time and space of the failure area of the ion-based rare earth tailings pile during deformation and failure are analyzed,which is helpful for the local collapse of the ion-based rare earth tailings pile under the influence of rainfall infiltration Meanwhile,it also provides theoretical basis for the prevention and control of the sliding damage disaster of ion-based rare earth tailings pile.The main research results and conclusions are as follows:(1)The influence of different slope top forms on the rainfall infiltration law and failure mode of ion type rare earth tailings pile is different.The pore water pressure,water content and drainage speed of the tailings pile model with slope top platform are larger,and the change is more sensitive.Moreover,under the condition of continuous rainfall,the tailings pile model with slope top platform is more likely to lead to landslide failure.(2)According to the influence of different rainfall types on the ionic rare earth tailings pile,the failure modes of the tailings pile model under the three rainfall types are basically the same,they are all shallow failure at the beginning of slope toe,extending upward to collapse failure.The main reason is that there are differences between before and after the failure time.Under the condition of front peak type rainfall,the tailing pile model needs the least time for large-scale failure,and its moisture content and pore water pressure are the most sensitive.The twodimensional area and three-dimensional volume of the deformation failure area are the first to show numerical changes,and the changes are mainly concentrated in the stage of heavy rain,and the failure tends to be stable and balanced at the earliest;the center front type rainfall strip After the numerical changes of the two-dimensional area and three-dimensional volume of the deformation and failure area of the rare earth tailings pile,the large-scale failure time is mainly concentrated in the first heavy rain stage to the heavy rain stage.After the heavy rain,the deformation and failure of the tailings pile is not very obvious,and the deformation and failure tend to be stable;the tailing pile model under the condition of post peak rainfall takes the longest time for large-scale failure,including The change of water rate and pore water pressure is the slowest,and the two-dimensional area and three-dimensional volume of the deformation and failure area of tailings pile show the latest numerical change.After the deformation and failure of tailings pile begins,it continues to slow down until the second half of the rainstorm.(3)According to the influence of different slope angle on the ionic rare earth tailings pile,the ionic rare earth tailings pile model with small slope angle is relatively stable,and the failure mode is generally from the initial shallow failure to the final collapse;the ionic rare earth tailings pile model with large slope angle has poor stability,and its failure mode is not only from the initial shallow failure to the subsequent collapse In the process of collapse,it is easy to produce sliding failure.During this test,the water content and pore water pressure of the ion-based tailings pile model with a slope angle of 30 ° have a long duration;the water content and pore water pressure of the ion-based tailings pile model with a slope angle of 45 ° basically maintain a stable balance after the heavy rain;the ion-based tailings pile model with a slope angle of 60 °,In the second stage,the pore water pressure at five locations has reached a stable equilibrium.(4)It can be seen from the analysis of the two-dimensional area and three-dimensional volume of the deformation and failure area,as well as the two-dimensional area change rate and three-dimensional volume change rate of the ionic rare earth tailings heap model in five groups of tests: in the same group of tests,the two-dimensional area change rate of the deformation and failure area of the ionic rare earth tailings heap model and the peak value of the corresponding three-dimensional volume change rate realized The carvings are similar.At the same time,the two-dimensional area and three-dimensional volume of the deformation and failure area of the ionic rare earth tailings pile model and the rate of change are not synchronous because of the deformation and failure of the ionic rare earth tailings pile model from the slope toe first,and the failure depth of the deformation and failure area changes indefinitely.