【摘要】 目前核电领域考虑地震动非相干性的土-结相互作用分析主要为频域方法，其在考虑土体强非线性和接触非线性方面存在不足。本文考虑时域分析方法，首先采用相干效应分解和多尺度方案对采用Cholesky分解的非相干地震动条件模拟方法进行了改进，使其可稳定高效地模拟大规模非相干地震动场；然后以非相干地震动场作为输入，采用PASSI方法进行土-结相互作用分析。采用上述时域方法，以CAP1400核电结构模型为例，分析了地震动非相干性对其反应的影响。算例结果表明：（1）本文提出的条件模拟改进方法可以用于大规模非相干地震动场的模拟，模拟结果可以反映所采用的相干模型特性；（2）地震动非相干性加大了核电结构位移反应峰值，在控制点地震动主要频段范围，地震动非相干性略微增加了低频加速度反应谱值，减小了中高频反应谱值。更多还原

【Abstract】 In the nuclear power sector, frequency-domain analysis is commonly employed for soil–structure interaction(SSI) considering the incoherence of ground motions. However, this approach has limitations in accounting for the strong nonlinear behavior and contact nonlinearity of soils. To address these shortcomings, this study adopts a time-domain analysis method. An incoherence effect decomposition and multiscale scheme are first introduced to enhance a conditional simulation method—based on Cholesky decomposition—for generating incoherent ground motion fields. These improvements ensure that the simulation of large-scale incoherent fields is both stable and computationally efficient. The simulated incoherent ground motion fields are then used as input for time-domain SSI analysis using PASSI. Using the CAP1400 nuclear power plant structure as a case study, the effects of incoherent ground motions on structural response are evaluated. The main findings are as follows:(1) The improved conditional simulation method proposed in this study effectively generates large-scale incoherent ground motion fields, and the results faithfully capture the statistical characteristics of target coherence models.(2)The incoherence of ground motions leads to an increase in peak displacement responses of nuclear power structures. It slightly amplifies the low-frequency acceleration response spectrum, while it reduces the mid-and high-frequency spectral amplitudes within the dominant frequency range of ground motion at control points.更多还原