Abstract：Maopingxi high rockfill dam is the accessorial dam of Three Gorges Project(TGP)，which is also the highest rockfill dam with asphalt concrete core in China. The deformation rules of the dam when the water level of TGP reservoir reaches to 135 m are analyzed；and the parameters of filling materials are back analyzed. Based on the parameters of back analysis，the behaviors of core wall and the dam are studied by nonlinear FEM when the water level of TGP reservoir reaches to the elevations of 156，165，172，and 175 m(the planed level)，respectively. Effects of parameters of the asphalt concrete on behaviors of core wall are analyzed. Furthermore，a function of hyperbola combined power is adopted in modeling the curves of long-term triaxial creep test of the asphalt concrete；and creep analysis is performed for the dam. Results show that the displacement in horizontal direction and the maximum principal stress of core wall will increase to a larger extent if the creep effect of asphalt concrete is considered. The study results also show that different water level procedures have small differential effects on the behaviors of core wall；and there is little probability of hydraulic fracture，shear and bend failure to the core wall. These results can be referenced to the plan of water level procedures on the dam；and the behaviors of high rockfill dam with asphalt concrete core under high water head are studied.
