In hydraulic structures design, using cutoff walls is essential to reduce and control the resultant uplift force (U), seepage discharge (Q), and exit hydraulic gradient (i). This research investigates the effectiveness of inclined double cutoff walls under hydraulic structures, considering the influence of depths, locations, and inclination angles of the upstream and downstream cutoff walls by using Finite Element Method (FEM). The results confirmed that installing a deeper cutoff wall on the downstream reduces the exit gradient even further. In the case of the cutoff walls located in the upstream and downstream ends, the exit gradient will be less than when the cutoff walls are installed at a closer distance. Increasing the inclination angle of downstream cutoff wall has a major impact on exit gradient reduction. Embedment of cutoff walls in the upstream and downstream ends with right angles and equal depths reduces the seepage discharge more than other cases.

在水工结构设计中，使用截流墙对于减少和控制合力（U）、渗流（Q）和出口水力梯度（i）是必不可少的。）。本研究使用有限元方法 (FEM) 研究了倾斜双防渗墙在水工结构下的有效性，考虑了上下游防渗墙的深度、位置和倾斜角的影响。结果证实，在下游安装更深的截流墙可以进一步降低出口梯度。在截流墙位于上游和下游端的情况下，出口坡度将小于截流墙安装在较近距离时的情况。增加下游截流墙的倾角对出口梯度降低有重大影响。在上游和下游端嵌入直角等深度的截流墙比其他情况更能减少渗流排放。