Quantitative 3D imaging of partially saturated granular materials under uniaxial compression
Quantitative 3D imaging of partially saturated granular materials under uniaxial compression
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DOI：
10.1007/s11440-021-01315-5
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发表时间：
2021-08
期刊：
影响因子：
5.7
通讯作者：
M. Milatz;Nicole Hüsener;E. Andò;G. Viggiani;J. Grabe
中科院分区：
文献类型：
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作者：
M. Milatz;Nicole Hüsener;E. Andò;G. Viggiani;J. Grabe
测量颗粒材料中部分饱和的机械效应在实验上是具有挑战性的，因为大孔隙导致的吸力非常低。为此，单轴（零径向应力）压缩试验可能优于三轴试验，其中围压和膜效应可能会消除这种小吸力的贡献;然而，体积变化是具有挑战性的测量。这项工作解决了这一限制，通过使用X射线成像duringinsitually单轴压缩测试汉堡砂和玻璃珠在三个不同的初始水含量，允许一个吸力依赖性膨胀带来的光。所获得的层析体积还允许空气-水和固体-水界面区域、水簇和局部应变场的发展在颗粒尺度上进行测量。这些测量被用于在剪切过程中测量相关的微观尺度量，并将它们与所测量的宏观响应相关联。在这次实验活动中获得的新的和良好的控制数据有望对建模工作做出有用的贡献，为此，它们与社区共享。
Gauging the mechanical effect of partial saturation in granular materials is experimentally challenging due to the very low suctions resulting from large pores. To this end, a uniaxial (zero radial stress) compression test may be preferable to a triaxial one where confining pressure and membrane effects may erase the contribution of this small suction; however, volume changes are challenging to measure. This work resolves this limitation by using X-ray imaging duringin situuniaxial compression tests on Hamburg Sand and glass beads at three different initial water contents, allowing a suction-dependent dilation to be brought to the light. The acquired tomography volumes also allow the development of air–water and solid–water interfacial areas, water clusters and local strain fields to be measured at the grain scale. These measurements are used to characterise pertinent micro-scale quantities during shearing and to relate them to the measured macroscopic response. The new and well-controlled data acquired during this experimental campaign are hopefully a useful contribution to the modelling efforts—to this end they are shared with the community.