Effects of compaction on soil undrained shear strength deteriorating during undrained cyclic loading and controlling seismic stability of embankment
Effects of compaction on soil undrained shear strength deteriorating during undrained cyclic loading and controlling seismic stability of embankment
复制标题
压实对不排水循环荷载过程中土体不排水抗剪强度恶化的影响及对路堤地震稳定性的控制
DOI：
10.1051/e3sconf/20199218003
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发表时间：
2019
影响因子：
--
通讯作者：
Ueno Kazuhiro
中科院分区：
文献类型：
--
作者：
Duttine Antoine;Tatsuoka Fumio;Ueno Kazuhiro
介绍了压实对饱和土坝材料不排水抗剪强度的影响。压实不良和压实良好的饱和土壤可能表现出分别显着低于和高于相应排水剪切强度的不排水剪切强度，并且随着不排水强度因之前的不排水循环荷载而恶化，这种趋势被放大。这些功能在新的简化地震分析中得到实现，以评估土坝的残余变形。该分析包括： 1) 改进的 Newmark 滑块分析； 2）伪静态非线性有限元分析，两者均基于累积损伤概念、总应力地震反应分析以及通过三轴试验获得的不排水单调和循环应力-应变行为的直接总应力建模，在统一框架中制定。该分析很好地模拟了 2011 年日本东北太平洋沿岸地震中土坝的倒塌，并表明在相同条件下，2017 年新修复的大坝的地震稳定性要高得多。证明了土壤压实对土坝地震稳定性的重要影响。
Effects of compaction on the undrained shear strength of saturated earth-fill dam materials are presented. Poorly and well compacted saturated soils may exhibit undrained shear strengths, respectively, significantly lower and higher than corresponding drained shear strength and this trend is amplified as the undrained strength deteriorates by preceding undrained cyclic loading. These features are implemented in a new simplified seismic analysis to evaluate residual deformation of earth-fill dams. The analysis consists of: 1) a modified Newmark sliding block analysis; and 2) a pseudo-static non-linear FEM analysis, both formulated in a unified framework based on the cumulative damage concept, total stress earthquake response analysis and a direct total stress modelling of undrained monotonic and cyclic stress-strain behaviours obtained by triaxial tests. The analysis simulates very well the collapse of an earth-fill dam by the 2011 Off the Pacific Coast of Tohoku Earthquake, Japan, and indicates a substantially higher seismic stability under the same conditions of the newly restored dam completed in 2017. Paramount effects of soil compaction on the seismic stability of earth-filled dam are demonstrated.