Seismic studies of the rockfill dam generally assumed that the shock vibration direction is the direction of the main axis

without regarding the uncertainty of the direction of vibration;The current hydraulic specification did not give a clear define of the incident direction of the seizmic waves to consider the seismic stability of dams

and engineering practice has no unified understanding.Taking a rockfill dam as example

the equivalent viscoelastic model is used to conduct a seismic response analysis under different seismic input direction consider.The study compared the acceleration

the displacement and the main stress response at 24 different seismic input directions for the rockfill dam.The results show that 240° is the worst seismic input direction.When the input angle is 240°

the dam shake analysis violently and the dynamic stability is worst.On the whole

not consider the direction of the seismic input

the results are unsafe

there are limitations in engineering design.Relevant laws and conclusions presented in this paper can provide the technical basis and reference for seismic design.