Seismic Responseanalysis Of A3-D Canyon In A Layered Half-space

Canyon site is a sort of common local topography in practical project. The studyon the motion chatacteristics of the canyon site not only can deepen our understandingon ground motion, but also can provide reasonable design parameters and basis forstructures seismic design.In this paper, the scattering of plane S wave by a3-D canyon site is studied byusing the viscoelastic artificial boundary method on the interception of the mediumboundary. This paper firstly studied the scattering of plane S wave by the3-Dhemispherical canyon under different frequences. The results have been comparedwith the obtained results, and the correctness and calculation accuracy of the researchmethod have been verified. Then this paper studied the scattering of the harmonicwave and EI Centro wave by the3-D hemispherical canyon in the homogeneoushalf-space, the bedrock under single soil and bedrock under layered soil site. Weanalyzed the impact of the incident wave frequence,bedrock and layered medium onthe site response.Research results show that, due to the presence of the canyon, site response iscompletely different from the free field response. Under the action of verticalincidence plane S waves, the surface displacement amplitudes depend on numerousparameters. Considering the bedrock and layered medium, the surface displacementamplitudes are significantly enlarged compared with homogeneous elastic half-space.With the increase of the incident wave frequency, the surface displacement amplitudedistribution becomes complex gradually and the displacement amplitudes show adecreasing trend in general.