A study on long-period response spectrum of ground motion affected by basin structure of Beijing

We built an underground 3-dimensional velocity structure model including topography, and simulated three earthquakes spreading through the basin by finite difference method. Then we computed the ground acceleration response spectrum, and analyzed its effective period span, and acquired its average amplification factor on long-period part, which is related to basin structure. After that, we made the zonation of amplification factors on different period, giving seismic fortification references for planning rational city layout and building long-period structures. Finally, we studied the relationship between amplification factor and sediment thickness, and drew the following conclusions: the amplification factor is increasing with thickness of sediment, and degrading with period.