This paper presents a numerical analysis of two types of representative site profiles in the Yinchuan Plain under earthquake loading. The analyzed soil profiles, based on borehole investigations performed over the years, are used to explore the seismic response of the sites in this area. In total, eleven stratified soil models are used in this study, which can be grouped into two categories: a single interbedded soil model and multiple interbedded soil model. A one-dimensional equivalent linearization method is applied to evaluate the seismic response of different soil models under four exceeding probabilities in terms of peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and spectral acceleration (Sa). The results show that the significant amplification effect of PGA occurs in rare and extremely rare earthquakes, with an amplification ratio of 1.4∼1.7 when the single silty clay layer is located at the model ground. In this scenario, the spectral acceleration is amplified at a period of approximately 1.0 s. For the multilayered soil cases, the amplification effect tends to decrease, whereas the characteristic periods increase with increasing numbers of soil layers and the ground acceleration is deamplified under a high motion intensity when the number of soil layers is ≥ 5. This study, to a certain degree, has reference value for seismic microzonation in this area.

中文翻译：

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银川冲积平原互层土层地震作用研究

本文对地震荷载作用下银川平原两类代表性场地剖面进行了数值分析。基于多年来进行的钻孔调查，分析的土壤剖面用于探索该地区站点的地震响应。本研究总共使用了 11 个分层土壤模型，它们可以分为两类：单互层土壤模型和多互层土壤模型。应用一维等效线性化方法评价不同土模型在峰值地面加速度（PGA）、峰值地速度（PGV）、峰值地面位移（PGD）和谱加速度（秒一种）。结果表明，PGA的显着放大效应发生在罕见和极罕见地震中，当单粉质粘土层位于模型地面时，放大比为1.4～1.7。在这种情况下，频谱加速度以大约 1.0 秒的周期放大。对于多层土的情况，放大效应趋于减小，而特征周期随着土层数的增加而增加，并且当土层数≥5时，在高运动强度下地面加速度去放大。一定程度上，对本区地震微带划分具有参考价值。