Study On Seepage Safety Of Fandongcun Tailings Dam In Dabaoshan Mine

The safety of tailing pond used for storing tailings after ore dressing has been concerned by many aspects.Once the tailings dam is unstable,it often causes great loss of life and property.Roller compacted rockfill dam is one of the main types of earth and rock-fill dam.Due to its high strength,good extensibility,aging resistance,good anti-seepage performance,and the ability of slope drainage,geomembrane products are suitable and economical as the anti-seepage material for rock-fill dams.There are many advantages of geomembrane for use,but its anti-seepage ability depends on the integrity of geomembrane,which may be damaged in construction and operation.Therefore,the anti-seepage reliability of geomembrane may be a disadvantage.The Fandong village tailings dam of Dabaoshan mine in Guangdong province is a Geomembrane anti-seepage rockfill dam.After being put into operation,there is continuous seepage water flowing out of the downstream,and the flow fluctuates around 12,000 m~3/d.Due to lack of monitoring of the seepage line,The source of water flowing from the downstream slope of the dam and the integrity of the geomembrane are two puzzling questions.Based on site inspections,basic data analysis,the chemical analysis of water and the finite element analysis of seepage calculation,this paper conducts an in-depth study on these two problems and obtains the following conclusions:(1)according to the chemical analysis of water and the water situation of the pond,that the water seeping into the catchment mainly comes from the eastern gully;(2)according to the water analysis and the finite element analysis of seepage calculation,the permeability coefficient of the equivalent anti-seepage layer of the geotechnical film is k=7.7e-8m/s,which is equivalent to that there is a 50cm thick anti-seepage clay inclined wall in the upstream dam slope,and the geotechnical film is in good condition;(3)The seepage safety at the end of the tailings pond is calculated and evaluated If the reservoir water level reaches 536m,and there is no dry beach before the dam,the seepage flow will escape from the downstream slope surface,and the dam body does not meet the seepage control requirements.However,if the reservoir water level is controlled below 533m and there is 70m dry beach before the dam,the seepage flow will escape from the downstream slope of the reverse pressure platform,and the dam body meets the seepage control requirements.