Assessing the dynamic stability of earth slopes is an important topic in geotechnical engineering field. In this study, the duration effect on the seismic performance of a multi-layer earth slope is quantitatively investigated, using two pairs of ground-motion suites selected matching a scenario-based response spectrum and a design spectrum, respectively. The four ground-motion suites are selected from the NGA-West2 database, with each pair of suites exhibiting a consistent distribution of response spectra yet different distributions of significant duration. Numerical analyses using the selected ground-motion suites as input are then conducted for the earth slope implemented in FLAC. Comparative results indicate that as compared to the shorter-duration suites, using the longer-duration ground-motion suites generally yields similar topographic acceleration-amplifications but an enlarged distribution of permanent slope displacements. Therefore, the influence of ground-motion duration on seismic-wave amplifications is insignificant; such influence on the earthquake-induced slope displacements is, however, significant. Using the selected longer-duration ground-motion suites, the slope (moderate) damage and failure probabilities exceeding specific displacement thresholds are increased by up to 20% and 50%, respectively. Therefore, when assessing the seismic performance of earth slopes in applications, one should pay adequate attention to the ground-motion duration effect, and input motions shall be selected in such a way that the duration characteristics of ground-motion records are properly constrained.

评估土坡的动力稳定性是岩土工程领域的重要课题。在这项研究中，通过选择分别与基于情景的响应谱和设计谱相匹配的两对地面运动套件，定量研究了持续时间对多层土坡抗震性能的影响。从NGA-West2数据库中选择了四个地面运动套件，每对套件都显示出一致的响应频谱分布，但是不同的持续时间分布。然后使用选定的地面运动套件作为输入，对FLAC中实现的土坡进行数值分析。。比较结果表明，与较短持续时间的套件相比，使用较长持续时间的地震动套件通常会产生相似的地形加速度放大倍数，但会增大永久性边坡位移的分布。因此，地震动持续时间对地震波放大的影响很小。然而，这种对地震引起的边坡位移的影响是巨大的。使用选定的较长持续时间的地面运动套件，超过特定位移阈值的斜率（中度）损坏和破坏概率分别增加多达20％和50％。因此，在评估应用中的土坡抗震性能时，应充分注意地震动持续时间效应，