Abstract: This paper explored the various effects of far and near field earthquakes by investigating the rocking response and bearing states of nuclear power isolation structures under both far and near field vibrations. The influence of seismic characteristics on the structural swing response was discussed, including the swing angle of the superstructure, tension and compression stresses, and shear displacement of the isolation bearings. The swing angle of the superstructure increased linearly with an increase in the acceleration amplitude. Moreover, the swing angle of the superstructure caused by near field vibration was larger than that caused by far field vibration, with greater discreteness. When the acceleration amplitude was 1.2 g, the mean and standard difference of the swing angle of the superstructure caused by near field vibration could reach 2.88 times and 3.90 times those caused by far field vibration, respectively. Near field vibrations were more likely to cause the bearing to enter a state of unsteady deformation, and appear to be in a state of tension. This paper provided engineering reference values for the seismic isolation design of nuclear power structures.

Key words: far and near ?eld earthquakes, rubber bearing, rocking e?ect, nuclear power structure