Abstract：In this paper, the time-domain calculating method for dynamic interaction between gravity dam and foundation object to obliquely incident seismic waves is developed based on hypothesis of homogeneous foundation, in which both oblique plane SV wave and oblique plane P wave are input simultaneously at artificial boundary and produce similar seismic response to the design seismic component at surface of half space. According to theory of wave propagating in solid, both incidence angles and amplitudes of the oblique waves have deterministic relation. Taking the interaction between gravity dam and foundation as an example, the time-domain seismic response is calculated and analyzed. The preliminary results show that obliquely incident seismic waves have greater influence to area nearing interface of dam foundation than other area, where the dynamic response under obliquely incident seismic waves is more than that under vertical incident seismic waves. The method takes both design seismic component and radiation damping of foundation into account, and produces nonuniform motion at interface of structure and foundation, so it can well be used to study dynamic response of structure under nonuniform input.
2011, Vol. 30 
