The main dam for the upper reservoir of the Tianhuanping pumped storage power station is a rockfill dam with an asphalt concrete impervious lining on the upstream face constructed on a full weathering rock foundation. In this paper, we present the case study on the treatment for this full weathering rock dam foundation. The treatment includes the partial excavation of the full weathering rock at the main dam foundation, the increase of the transition curvature at the parts where the lining is extended from the upstream face to the reservoir bottom and turned to both the left and the right banks, and the reinforcement for the asphalt concrete impervious lining with a layer of polyester mesh at the parts where the tensile strain of the lining is large. A 3D FEM analysis is carried out for the main dam. The calculated results provide a good basis for the above compound treatment method. So far, this project has operated well for more than three years, illustrating the success of the treatment for the full weathering rock dam foundation
