Abstract: The drainage hole is an important seepage control measure, so it is one of the key problems to simulate the effect of the drainage hole in the seepage analysis. Although the substructure method is an effective and popularized method, its mesh generation, which is dependent on the global mesh, is still a difficult task in engineering practice. A novel method named superposed element method (SEM) is proposed to simulate the drainage holes. Firstly, the structure containing drainage holes is divided into two independent meshes. One is the global mesh without drainage holes, and the other is the local mesh of the drainage hole together with its adjacent zone. Then, the two independent meshes are coupled together through the virtual seepage on the outer interface of the local mesh. Finally, two numerical examples are studied, in which the effect of the drainage holes can be simulated accurately. According to the results of the sensitive analysis, the proper range of the local mesh is 1–3 times of the element length in the global mesh; and the permeability coefficient of the outer interface is suggested to be 102–103 times of the material permeability coefficient. Since the mesh generation of the superposed element method is quite simple, the new method is expected to be widely used to solve complicated seepage problems in engineering practice

Key words: seepage, drainage hole, superposed element method, finite element method