Simplified lumped-parameter model in nuclear power standards have been commonly applied for ground-nuclear island structure interaction investigation. However, when considering the fine far-field radiation damping effect, the previous simplified models cannot reflect the correlation of the infinite-domain dynamic impedance function with respect to the excitation frequency as well as take into consideration the non-homogeneity of layered ground. Furthermore, the global coupling characteristics of the high-precision artificial boundaries will lead to a sudden increase in the computational cost. In this study, a large-scale calculation method for nuclear island structures through the scaled boundary finite element method (SBFEM) is developed, which can consider the embedded effect and is applicable to the coupling of the dynamic impedance function under layered ground conditions. A method of decoupling the near and far field interface domain is introduced, which solves the full matrix storage limitation for dynamic stiffness (DS) matrix according to original SBFEM, and adopts the partitioned parallel technique to improve the inverse efficiency of large matrices in the process of dynamic condensation. Numerical examples show that the proposed algorithm has good accuracy and applicability for different foundation shapes, foundation embedment effects, and layered characteristics of ground, and provides engineering references for the calculation of dynamic impedance function under large-scale nuclear power plants.
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