For assessed knitted fabrics in this study, both a saturated zone and an unsaturated zone in vertical wicking were found though in horizontal wicking the unsaturated zone did not significantly exist in the sample strips.

Taking the actual situation of project as a background,and considering the influence of the unsaturated zone of the earth-rock dam and size of core wall in different circumstances,seepage calculation is carried out to discuss the distribution of seepage field and change rule of free surface.

This paper makes an approach to the distribution condition of seepage fields and the laws of change of free seepage surface by means of seepage calculation and analysis for different volumes of the core wall taking into account the influence of unsaturated zone according to the actual conditions of the project.