This paper builds a mixed analytical model for based-isolated CPR1000 reactor structure

in which superstructure and raft foundation are modeled by lumped mass-beam elements and three-dimensional solid elements

respectively.A complete base isolation design of CPR1000 reactor structure is presented in this paper.The lead-rubber bearings are placed under the raft foundation.The surface pressure of lead-rubber bearings is about 5 MPa.The dynamic behavior of base-isolated reactor structure is investigated.Nonlinear time-history analysis of the isolated nuclear power plant structure is carried out.The shears and overturning moments of the based-isolated reactor structure are compared with the base-fixed structure.In addition

floor response spectrum of the base-isolated CPR1000 reactor structure is set up for analysis of the internal equipment and compared with the base-fixed case.Results show that the mixed analytical model for reactor structure possesses enough calculating efficiency and precision.Base-isolated technology can significantly reduce the shears

the overturning moments and the floor response spectrum of the reactor structure

and enhance its safety greatly.