Numerical Simulation And Engineering Application Of Valley Tailings Ponds Failure

By the end of 2017,there are 7,793 tailings ponds in China,most of which are valley-type tailings ponds.The tailings pond is quite special,taking into account the functions of storing tailings and water,and has the characteristics of high potential energy and high risk.Two-thirds of the total tailings accidents were dam failures,especially in Shanxi,which caused a particularly serious dam failure,resulting in 281 deaths.Therefore,the study of numerical simulation of valley tailings pond has typical and wide application characteristics and has universal guiding significance.This thesis studies the relationship between the theoretical analysis of the instability of the tailings pond and the application of numerical simulation,analyzes the relationship between the risk indicators of the tailings reservoir and the dam;analyzes the relationship between the dam height and the slope on the structural stability of the dam,and further studies the dam.The variation law between dam height and slope and safety factor when the body is increased and expanded;the change trend of stress and strain of dam under earthquake action,the change of internal structure displacement of dam body and liquefaction;and the countermeasures for safe operation of tailings pond Measures.The conclusions are as follows:(1)On the basis of statistically summarizing the distribution of tailings reservoir,the basic situation of larger accidents and analyzing the risk of instability of tailings reservoir,the risk index system of tailings pond dam breakage is established.(2)The rate of decrease of the saturation line height is related to the height of the dam and the upstream water level.The high dam body is prone to osmotic damage at high water level.(3)The slope is constant,and the higher the height of the dam,the lower the safety factor of the slope.The dam height is certain,the smaller the slope,the higher the safety factor of the slope.(4)When the sub-dam is built for expansion and expansion,the change trend of the slope stability coefficient under different sub-dam height and pile-slope ratio conditions is consistent with the change of the height of the initial dam.(5)Under the action of earthquake,the deformation of the dam mainly occurs near the dam slope,and the effective stress is gradually reduced.The local pore water pressure increases with the earthquake time and has a linear relationship.The liquefaction zone after the earthquake shows that the underwater part of the tailings sand is in a saturated state for a long time,and the middle and lower parts of the tailings dam body are also prone to earthquake liquefaction.