In this study, the lateral resistance and bending moment of a wind turbine foundation reinforced with piles on the bedrock were evaluated through modeling tests considering the cross-sectional size and presence of piles. The lateral resistance of a small foundation (16 m) with piles was found to be 1.84 times greater than that of the existing wind turbine foundation (20 m). After installing eight piles in the wind power turbine foundation, the outer and inner circles were compared, and the lateral resistance at the outer circle with piles was found to be the largest. Moreover, the lateral resistance force was similar for the series, parallel, and diagonal arrangements of six piles. The bending moment increased based on the order of the front, right, and back rows. The maximum bending moment of the pile for the front row was observed at the interface between the wind turbine foundation and rubble bed, while that for the right and back rows was observed at the interface between the rubble layer and bedrock.