Theseismic responses of soil-pile-isolation pedestal-nuclear island structure andsoil-pile-nuclear island structure were studied by large-scale simulatedshaking table test. In the test

rubber lead-zinc bearing was used asfoundation isolation and placed between pile foundation cap and upper nuclearisland structure. The foundation soil was uniform silty clay from anengineering site. The ground motion time history was fitted by RG1.60 responsespectrum designed by Nuclear Power Corporation of the United States. The testresults show that the isolation bearings can not only change the frequency ofthe superstructure

reduce the acceleration and the magnitude of the responsespectrum

but also dwindle the bending moment of the lower pile

which canreduce the reaction isolation of the superstructure. However

the use ofisolation bearings will change the bending moment distribution of pilefoundation

thus special seismic design should be made for pile foundationstress and deformation in nuclear power engineering to ensure the seismicstability of the whole soil-pile-superstructure system