The use of Newmark permanent displacement to preliminarily evaluate the seismic performance of earth slopes has been well accepted in geotechnical community. Essentially, the seismic displacement would cause slope soil shear strength to reduce, thus causing the slope yield acceleration to degrade during the earthquake shaking. This phenomenon is known as degrading effect of yield acceleration, which has not been fully addressed in the literature. In this study, the degrading effect is investigated on the basis of various Newmark's displacement calculation frameworks for infinite slopes. Specifically, the flexible-deformation-recoverable soil columns as well as the nonlinear soil dynamic properties including the damping and shear modulus are taken into account to derive the coupled Newmark model. Detailed discussions are made to the possible influence of the degrading effect of yield acceleration in different schemes of Newmark displacement calculation frameworks. The parametric studies show that the seismic displacement calculated by the proposed method reaches peak value at small period ratio, and dramatically drops to zero when the period ratio increases. Furthermore, the possible influence of shear rate on soil shear strength is also discussed.

中文翻译：

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具有降级屈服加速度的简化非线性耦合Newmark位移模型用于边坡稳定性分析

使用 Newmark 永久位移初步评价土坡的抗震性能已被岩土界广泛接受。本质上，地震位移会导致边坡土体抗剪强度降低，从而导致地震震动过程中边坡屈服加速度降低。这种现象被称为屈服加速的退化效应，在文献中尚未完全解决。在本研究中，基于各种 Newmark 的无限边坡位移计算框架，研究了退化效应。具体而言，考虑柔性变形可恢复土柱以及非线性土动力特性，包括阻尼和剪切模量，以推导出耦合纽马克模型。详细讨论了Newmark位移计算框架不同方案中屈服加速度的退化效应可能产生的影响。参数研究表明，该方法计算出的地震位移在小周期比时达到峰值，当周期比增加时急剧下降为零。此外，还讨论了剪切速率对土壤剪切强度的可能影响。