Causes Analysis of Leakage in a Geomembrane Anti-seepage Earth-rockfill Dam
As geomembrane is widely used in reservoir dam seepage prevention,dam leakages caused by geomem-brane defects seriously threaten the safety of reservoirs and engineering benefits.Aiming at the problem of the main dam of a geomembrane anti-seepage regulation reservoir,this paper established a finite element model to calculate the impact of the location and size of geomembrane defects on the main dam's infiltration line,seepage field potential,and other seep-age characteristics,and the causes of leakage were analyzed.The causes were verified by combining high density electrical methods,safety monitoring data,and supplementary geological surveys.The results show that the reason for the leakage is that the compactness of the filling soil in the main body is low and partially collapsible,which leads to the large settle-ment of the main dam and the damage of the geomembrane caused by tension.As the defect position of the geomembrane moves upward,the elevation of the infiltration line presents a trend of first increasing and then decreasing,and there are local protrusions.The post-membrane disinfecting water head decreases slowly with the increase of the defect size of the geomembrane,and with the defect position moving up,it is basically unchanged at first and then increases significantly.The geomembrane was damaged near the junction of the upstream dam slope and the bottom of the reservoir at the section of stake No.0+070,and near the upstream horseway of the section of stake No.0+270.The research results can pro-vide reference for risk diagnosis,design and operation management in similar projects.
storage reservoirgeomembrane defectsleakagenumerical simulationhigh density electrical method
万方数据
维普
