The main shock measured by stations of China strong motion networks center(CSMNC) around Zipingpu concrete face rockfill dam(CFRD) and the aftershock measured by Zipingpu stations are analyzed. The basic characteristics of strong ground motions are studied. Three-dimensional dynamic finite element analysis is adopted to analyze Zipingpu CFRD while the main shock measured by stations like Diban of Mao county(DBM)

Zoushishan of Pi county(ZSP)

Zhonghe of Chengdu(ZHC) and recorded aftershock of rock stations on dam site on Nov. 6

2008 and artificial ground motion generated by standardized spectrum of specifications for seismic design of hydraulic structures as seismic input; and then comparison between the finite element data and the measured data is made. It is shown that the long period component (0.65 s later) of response spectrum of ground motion recorded by stations of ZSP and ZHC is much too rich as these far-field stations locate in the footwall of fault. As Zipingpu dam locates near the fault

main shock recorded by far-field stations can not be used as seismic input. The components in the range of about 1 Hz (base frequency of the dam) of the aftershock recorded by stations of Zipingpu dam are lower and the duration is less so that it is difficult to stimulate the dam. Compared with measured and calculated spectra on dam crest

ground motions measured by Diban station of Mao county and artificial ground motion generated by standardized spectrum are suggested to be used in dynamic analysis of Zipingpu dam during Wenchuan earthquake.