The multi-fault rupture of large earthquake will lead to changes in the shape of the ground motion time history and more severe damage.In order to reveal the influence of multifault rupture on the ground motion characteristics

the attenuation relationships of the peak

the duration and the response spectrum of single-and double-plateau ground motions were deduced based on the 5·12 Wenchuan earthquake records.The differences between the single-and double-plateau ground motion parameters were compared.The results show that the peak

duration and response spectrum of the double-plateau ground motion caused by the multi-fault rupture are larger than those of the single-plateau ground motion.The changes of the single-and double-plateau ground motion parameters are the same with the increase of the fault distance

while the change rates are inconsistent.The change rates of the peak acceleration and energy duration of the double-plateau ground motion with the changing fault distance are higher than those of the single-plateau ground motion.The change rates of the peak velocity

absolute duration and acceleration response spectrum of the double-plateau ground motion with the changing fault distance are lower than those of the single-plateau ground motion.