Study On The Over-topping Evolution Law And Disaster Consequences Of Reinforcement Tailings Dam

Recently, the tailings dam accidents have frequently occurred caused by flood overtopping, which have great harmful to the downstream people`s lives, property safety and the surrounding environment. Based on similarity theory and principle of burst erosion model, according to unsteadiness fixed flow and sediment erosion mechanism of non-equilibrium theory, take the tailings in Yunnan as test materials. We used the physical model test method to establish an evolution model of the different reinforcement density tailings dam under flood situation, analyzed thoroughly the floating evolution of reinforced tailings dam and the retardative of bar strips during tailings dam failure process. The results indicate that:(1) Infiltration lines of the reinforced taillings dam have some hysteretic nature; with the increase of density of reinforcement, the mechanical strength of the dam is improved; however, it may cause the infiltration line too high in a short time;(2) The erosion gully of reinforced tailings dam hasn’t significantly continuous failure surface, it only horizontal expanded along the bar strips laying distribution, which ensured the stability of tailings dam; with the increase of density of reinforcement, the dam bursts only horizontal expanded, and the step appearance got more significantly;(3) the whole overtopping processes of the reinforced tailings dam can be concluded to five stages: the erosion gully formation stage�'the improvement of erosion gully, which got deepen stage�'erosion gully internal extended stage�'step appearance erosion gully formed stage�'step shape erosion gully in stable stage, the whole overtopping is significantly in step failure model;(4) the existence of the reinforced belts has obvious blocking effect on the developing speed of tailings dam destruction and the of depth、width of erosion gully, the vertical and horizontal displacement, also as the change of internal stress of reinforced tailings dam are significantly less than the unreinforced;(5) the reinforced belts improve resistance slip ability during the overtopping and prevent tailings scouring; which also have pull effect on both sides of erosion gully to ensure stability of the dam`s wings, further hindering the collapse of two wings by hydraulic scouring;The results have been deeply analyzed the evolution law and failure mode of tailings stacking dam, and reveal the blocking effect of reinforced belts during overtopping destruction, having some new exploration on prevention/control of flood disaster and mine disaster risk assessment.