Effects of induced anisotropy on multiple liquefaction properties of sand with initial static shear
Effects of induced anisotropy on multiple liquefaction properties of sand with initial static shear
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DOI：
10.1016/j.sandf.2019.03.015
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发表时间：
2019-10
影响因子：
3.7
通讯作者：
T. Morimoto;Yudai Aoyagi;J. Koseki
中科院分区：
文献类型：
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作者：
T. Morimoto;Yudai Aoyagi;J. Koseki
自2010-2011年的基督城地震和2011年的东日本大地震以来，多重液化现象引起了越来越多的研究人员和工程师的关注。然而，人们对斜坡地基的多重液化特性知之甚少。因此，在这项研究中，多次液化试验，考虑到初始静态剪切应力，这是从来没有进行过，进行了一个特殊设计的仪器，叠环剪切仪。一系列的多重液化试验表明，诱导各向异性，这是弱对加载相反的初始静态剪应力的方向，是由倾斜地面液化。结果，在下一个循环的剪切过程中，抗液化能力显着下降。从再固结过程、初始静剪应力的大小和液化阶段结束的类型等方面讨论了影响各向异性大小的指标。此外，在初始静剪应力较大的多次液化试验中，由于各向异性引起的大的负粘性，与初始静剪应力方向相反的剪应力较小，因此再液化阻力较高。
The multiple liquefaction phenomenon has been attracting the attention of more and more researchers and engineers since the 2010–2011 Christchurch Earthquakes and the 2011 Great East Japan Earthquake. However, little has been known about the multiple liquefaction properties of sloped grounds. In this study, therefore, multiple liquefaction tests that consider the initial static shear stress, which have never been conducted before, were carried out with a special designed apparatus, the stacked-ring shear apparatus. A series of multiple liquefaction tests revealed that induced anisotropy, which is weak against the loading opposite to the direction of the initial static shear stress, was produced by the liquefaction of a sloped ground. As a result, a significant decrease in the liquefaction resistance during the next cyclic of shearing occurred. The indicators which influenced the magnitude of anisotropy were also discussed from the perspective of the reconsolidation procedures, the magnitude of initial static shear stress, and the type of ending of the previous liquefaction stage. In addition, it turned out that in the multiple liquefaction test with a larger initial static shear stress, the re-liquefaction resistance was higher because the shear stress opposite to the direction of the initial static shear stress, causing large negative dilatancy due to anisotropy, was smaller in that test.