Abstract:  Yuecheng Reservoir belongs to the national key reservoir, while the reservoir area and the surrounding ground is a typical coalrich region, covering a large number of highquality coal resources. In order to study the impact of mining activities on the seepage of the dam and dam foundation, the dam was used as the research object and a safety limit in the upstream was set in this paper. By controlling the effective protection boundary of the dam and foundation, the impact depth and the impact degree of the mining on the shallow surface were controlled. The numerical simulation results showed that under the condition that the water level was 105.0 m upstream, 159.1 m downstream and the exploration impact distance was 2000 meters away from the dam, mining activities would not affect the permeability of the dam and the foundation. At the same time, it would not affect the permeability of the dam shoulder as well.

Key words:  coal mining protection boundary, saturatedunsaturated seepage flow, finite element simulation