Adopting anti-seepage curtain is an important dam anti-seepage measure ,however ,defects often occur during the process of grouting ,which has a bad effect on dam seepage control .So the grouting treatment seems very important for the defect area ,whereas the research on the effectiveness of curtain defect grouting is very rare .It was found that in a rockfill dam ,a high permeable area existed between the diaphragm wall and overburden curtain during the quality de-tection .Regarding to this problem ,curtain grouting treatment was adopted .To evaluate the influence of the overburden curtain grouting compartment on dam seepage field ,a 3D finite element method was used to analyse seepage flow change according to different thickness of the grouting compartment and different curtain seepage coefficients .Results showed that with the increase of grouting thickness ,the seepage flow quantity was reduced gradually .The gradient ratio was less than allowable value when the thickness reached 8 m ,which met the requirements for overburden curtain grouting area gradient ratio .Under the same thickness ,the ratio was decreased with the increase of the seepage coefficients ,while the flow rate through the overburden curtain grouting area was increased slightly .According to the analysis of this situation it is drawn that the decrease of gradient ratio is beneficial for the stability of the dam’s seepage field ,a slight increase on the flow do not influence the dam’s stability .%防渗帷幕是大坝防渗措施的重要组成部分，然而防渗帷幕在灌浆过程中往往出现缺陷，影响大坝的防渗效果。因此对缺陷区进行灌浆处理显得十分重--，然而对缺陷区灌浆处理后其效果的研究十分少见，针对某堆石坝在工程施工检测中防渗墙与帷幕之间存在高强渗透区现象，对该部分覆盖层进行帷幕灌浆处理。为定量评价该覆盖层帷幕灌浆区对大坝渗透场的影响，采用有限元方法进行了覆盖层帷幕灌浆区厚度以及渗透系数的敏感性分析。研究表明：随着覆盖层帷幕灌浆区厚度的增大，其渗透流量逐步减小，当覆盖层帷幕灌浆区厚度达8m 时灌浆区比降小于允许比降，满足帷幕渗透灌浆区比降要求；相同覆盖层帷幕灌浆区厚度条件下，渗透系数增大，其承受的比降有所下降，但会使透过覆盖层帷幕灌浆区的流量略有增大，降低比降有利于坝体渗透场稳定，流量略增大不影响坝体稳定。
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