Comparison of two-dimensional basin and sub-basin resonances under vertical incidence of SV and SH waves
In addition to the direct incident body wave at the bottom,the sub-basin in the basin and sub-basin also have laterally propagated surface waves generated by the large basin,which lead to the change of the resonance characteristics of the sub-basins.Based on the explicit finite element method,the effects of sub-basin impedance ratio,large-basin dip angle and half-width on the resonance frequency and amplification factor of two-dimensional trapezoidal basin and sub-basin under the vertical incidence of SH and SV waves are comparatively analyzed.The results show that:affected by the laterally propagating surface waves generated in the large basin,the maximum values of PGV and Exin the sub-basin are obviously amplified,and the amplification of SV waves is greater than that of SH waves.The sub-basin impedance ratio has a great influence on the maximum PGV,Ex,resonance frequency and amplification factor of the basin and sub-basin,while the dip angle and half-width of the large basin have little effect.Compared with a single small basin,the resonance frequency of the sub-basin increases under the incidence of SV wave and SH wave,with the value of incidence of SV wave greater than that of SH wave under the same impedance ratio.The amplification factor of the sub-basin under the incidence of SH wave is basically larger than that of the single small basin,while the SV wave is lower than the single small basin under the low impedance ratio,but higher than the single small basin and the SH wave incidence under the high impedance ratio.The resonance frequency and amplification factor of the basin and sub-basin are more affected under the incident SV wave than that of SH wave.
basin and sub-basinexplicit finite element methodtwo-dimensional basin resonanceimpedance ratio
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