Abstract
The wave field on the artificial boundary was separated into the free field without local topography effect and scattering field induced by local topography effect. The simulation of the free field under obliquely incident waves was conducted. Based on the assumption that the components of design ground motion were treated as the coincidence of oblique P wave and oblique SV wave, the relationship between the oblique input waves and the design ground motion was established in the free field. Further, the contributions to the two components of design ground motion of obliquely incident waves were discussed. The calculation model in time domain was achieved by the combination of the propagation characteristics of obliquely incident waves and the artificial boundary in the free field. The seismic response to the design ground motion was produced on the free surface. The verification of the 2D half-space model under oblique input waves indicated that the wave input method can accurately reflect the design ground motion on the free surface. Application of an earth-rock dam showed that oblique incidence of seismic waves results in significantly different dynamic response compared with the normal incidence. The proposed method can also be employed in the seismic analysis of large span structures with nonuniform ground motion input.
Highlights
Due to uncertainties of seismic ground motion input and complexity of dynamic response, the seismic safety of largescale structures is widely concerned
In order to ensure the security of large-scale structures under the action of near-field earthquake, the reasonable seismic input method is the vital basis of accurate seismic analysis
The wave field on an artificial boundary is separated into the free field without local topography effect and scattering field induced by local topography effect [6]
Summary
Due to uncertainties of seismic ground motion input and complexity of dynamic response, the seismic safety of largescale structures (e.g., high dams) is widely concerned. The seismic response analysis of the structures mentioned above was based on the case that the input wave was definite in free field. The input wave has some connection with the design ground motion on the free surface, it cannot entirely reflect the nature of the ground motion that the engineered structure site will be encountered in the future [10, 11]. To establish oblique incident wave field reflecting the design ground motion, the oblique plane SV wave and oblique plane P wave were developed from the one-way ground motion on the free surface [12]. The seismic response of the half-space model was the same as the design seismic component on the free surface when the obliquely incident waves were input simultaneously. The method of oblique input waves reflecting two components of design ground motion was established using the viscous-spring artificial boundary
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