抄録
This paper presents the effects of nonlinear behavior in horizontal stiffness and the decrease in vertical stiffness of rubber bearings on seismic response during large deformation in a horizontal isolation system of nuclear island buildings. This investigation is performed analytically. In order to examine the horizontal and vertical stiffness of full-scale bearings, rubber bearings of 4900 kN (500-ton) rated load are tested within the allowed range of horizontal deformation. To investigate the effect of nonlinear behavior in horizontal stiffness during large deformation, test results of small-scale models which have already been reported are used. Moreover, this paper comments on the design of rubber bearings taking into consideration nonlinear behavior during large deformation and the increase in stiffness due to aging.
