土?桩基?隔震支座?核岛地震反应试验研究

通过开展大型地震模拟振动台试验，对比研究了土?桩基?隔震支座?核岛结构和土?桩基?核岛结构的地震反应。试验采用橡胶铅锌支座作为基础隔震，放置于桩基承台和上部核岛结构之间，地基土采用某工程场地的均匀粉质黏土，试验输入的地震动时程，是由美国核电设计的 RG1.60 反应谱拟合而成。试验结果表明：隔震支座不仅可以改变上部结构频率、减小加速度和反应谱幅值大小，还可以减少下部桩的弯矩，起到降低上部结构的反应的隔震作用。但隔震支座的使用会改变桩基础的弯矩分布，核电工程采用隔震支座时应对桩基受力和变形进行特殊抗震设计，以保证土?桩?上部结构整体系统的抗震稳定性。

Experimental study of seismic response of soil-pile foundation-isolation support-nuclear island

The seismic responses of soil-pile-isolation pedestal-nuclear island structure and soil-pile-nuclear island structure were studied by large-scale simulated shaking table test. In the test, rubber lead-zinc bearing was used as foundation isolation and placed between pile foundation cap and upper nuclear island structure. The foundation soil was uniform silty clay from an engineering site. The ground motion time history was fitted by RG1.60 response spectrum designed by Nuclear Power Corporation of the United States. The test results show that the isolation bearings can not only change the frequency of the superstructure, reduce the acceleration and the magnitude of the response spectrum, but also dwindle the bending moment of the lower pile, which can reduce the reaction isolation of the superstructure. However, the use of isolation bearings will change the bending moment distribution of pile foundation, thus special seismic design should be made for pile foundation stress and deformation in nuclear power engineering to ensure the seismic stability of the whole soil-pile-superstructure system