Abstract：To build high earth-rockfill dam on thick moraine cover foundation in high earthquake intensity region will face many new problems such as dynamic stability，dam foundation liquefaction etc. As an example，three-dimensional dynamic consolidation FEM is employed to analyze the reaction of high earth-rock fill dam with clay core and cat-off wall. The dynamic stability is researched. An equivalent quasi-elastoplastic constitutive model which can express nonlinear viscid and un-recoverable deformation of soil is employed in the new dynamic consolidation FEM，while dynamic pore water pressure model is abandoned. The generation，diffusion and scatter of dynamic pore water pressure in a complete earthquake process are tracked. It is a real coupling of dynamic seepage and dynamic reaction. The calculation results show that the static stress and displacement of the dam on thick moraine cover foundation are bigger；the dynamic stress，displacement and acceleration are smaller；the ratio of pore water pressure in the dam base is smaller than the dam on rock foundation. The dam is safe.
