Seismic evaluation of nuclear structures under structure-soil-structure interaction: Effects of ray-tracing wave propagation and damping calibration

The adjacent distribution of different nuclear structures is a common engineering scenario. Since the Fukushima nuclear accident and with rapid advancements in hardware computational capabilities, the local seismic behavior resulting from the interactions between structures and layered soils is being revisited, with potential to become a crucial component of evaluation refinement. The domain reduction method characterizes the relative spatial layouts of structures and surrounding geology, capturing their nonlinear coupling behavior in an exogenous wave field. This study focuses on developing an efficient theoretical model and corresponding algorithmic framework that integrates the partitioned pattern of system matrices, calibration of damping parameters, and batch computation of seismic forces, aided by parallelization and GPU acceleration. The parametric study is conducted for typical scenarios and modular structures, and the following conclusions are drawn. Structure–soil–structure interactions potentially have adverse effects on seismic safety, as exemplified by floor response spectra. Adjustments to the design elevation differences may lead to change in the peak values of vertical floor spectra of nearly 45 %. Softer inter-building inclusions have damping effects, whereas harder inclusions increase the peak values. A high-accuracy ray-tracing wavefields perspective for the seismic evaluation of specific structure adjacency and complex sites is supported via the procedural strategy.