| Tailings as one of the three basic engineering of the mine,its importance to China is selfevident,due to the large number of tailings pond,caused a series of safety problems,due to flood tailings pond dam accident is numerous,caused significant damage to the middle and downstream areas,not only need a lot of human and financial resources,but also caused great pollution to the surrounding environment.In recent years,scholars at home and abroad have conducted many studies on the erosion and destruction of tailings ponds and achieved good results.However,it more considers the erosion and destruction of fine grain tailings under clear water conditions,but hardly studies the erosion and destruction mechanism of reinforced fine grain tailings under sand and water flow conditions.Therefore,the erosion height,quantity and rate of the destructive characteristics of multi-factor coupling.First,Granularity analysis was performed on the test samples,Ensure that all the test samples belong to the fine-grain range;Secondly,through the top hydraulic erosion test of large reinforced tailings dam,The concentration range of sand water is obtained,Through the sand erosion test and FLOW-3D software simulation,The erosion and mechanism of reinforced fine tailings sand is analyzed;Finally,the data were fitted with the MATLAB software,The high prediction model of hydraulic erosion and hydraulic erosion rate of reinforced fine-grain tailings are established.The research results can provide support for the subsequent erosion damage prediction of reinforced tailings dam,as follows:1.The variation characteristics of sand concentration in the flood top hydraulic erosion test of large reinforced tailings dams are clarified.By carrying out three sets of experiments with the number of rib layers of 2,3 and 4(that is,the spacing of the reinforcement is 30,50 and 70 cm),the erosion changes in the middle and lower reaches of the tailings dam were observed during the test,and the samples of erosion amount were collected in the middle and lower reaches of the slope,and through the drying of the samples,a graph of the curve change of sand concentration was obtained,and the value range was between 0% and 20%,and the concentration change increased linearly over time to reach the peak and then decreased.2.The influence mechanism between rib bands,fine grain content,sand concentration and tailings erosion failure was revealed.It can be seen from the erosion test of reinforced finegrained tailings under the flow of sandy water that with the increase of fine particle content,the surface of the tailings sample is eroded more uniformly,and at the same time,the final erosion height,erosion amount and erosion rate of reinforced tailings are inversely related to the number of ribbed layers,and the sand concentration of the water flow is positive.3.The animation process of hydraulic erosion failure of reinforced fine-grained tailings under the condition of sandy water flow is simulated by FLOW-3D software.Because the test is affected by the sandy water flow,it is impossible to observe the change of the test process with the naked eye,and the software simulation fills its shortcomings.The simulation results show that during the hydraulic erosion of the reinforced fine-grained tailings sand,the front end of the rib belt is not affected by the blocking effect of the rib belt on the water flow,and the degree of erosion is greater than that of the rear end of the rib belt,and the surrounding of the rib belt is affected by the vortex and is also damaged by a certain degree of erosion.4.A linear prediction model for hydraulic erosion of reinforced fine-grained tailings was obtained.Mat LAB software is used to fit and analyze the test data obtained after the erosion test of reinforced fine-grained tailings under the sandy water flow,and the effectiveness of the model is verified by comparing the calculated value with the test value,and the error value is obtained within a reasonable range of 6%,indicating that the prediction model is feasible.The research results of this paper can further enrich the theory related to the erosion failure characteristics of reinforced fine-grained tailings,and provide a theoretical basis for tailings erosion under subsequent sandy water flow conditions. |
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