Based on the explicit FE method and 32CPU parallel computing cluster platform of ABAQUS

a large-scale refined two-dimensional（2D）FE nonlinear analytical model for seismic micro-zoning site of Chuzhou city in Anhui province is established in the time domain.The influences of local geological conditions with different characteristics on the ground surface seismic response are emphatically analyzed.The results show that:the peak ground acceleration（PGA） will be amplified compared to the peak acceleration of input motion

the amplification effect of floodplain area presents especially remarkable.It presents a wider acceleration response spectra shape in floodplain area than that in first terrace area

meanwhile the spectra peak moves to a larger period in the floodplain area compared with that in first terrace area and the period difference comes to be from 0.05sto 0.25s.Besides the ground surface acceleration response spectra of floodplain area gradually appear a double-peak or multi-peak phenomenon and the corresponding characteristic period increases.In some way

the large-scale nonlinear analysis may reflect the nonlinear seismic response characteristics of the site

which will provide a reasonable basis for the earthquake zoning work of cities.