Non-invasive characterization of particle morphology of natural sands
Non-invasive characterization of particle morphology of natural sands
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DOI：
10.1016/j.sandf.2012.07.011
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发表时间：
2012-08-01
影响因子：
3.7
通讯作者：
Lee, P. D.
中科院分区：
文献类型：
--
作者：
Fonseca, J.;O'Sullivan, C.;Lee, P. D.
颗粒形态，即颗粒尺寸和形状，对包括土壤在内的粒状材料的力学响应具有显著影响。到目前为止，大多数颗粒形状的研究都是二维的，并且最常使用筛分来评估尺寸。本文利用三维成像技术的最新发展来表征土壤的三维内部特征，包括颗粒形态的量化。研究的土壤是Reigate砂（来自英格兰东南部），一种地质上古老的砂，在其完整的状态下，其组成颗粒之间表现出显着的互锁。在三轴压缩条件下，对具有相似密度的完整和重组样本进行了测试。在剪切变形的三个不同阶段用环氧树脂浸渍试样，并使用X射线显微断层扫描法对每个试样的小芯进行扫描。不同的系统和扫描参数进行了探讨，以获得三维，高分辨率，图像的体素大小为5 μ m（0.018 × d（50））。将形态测量结果与筛数据和使用2D基于图像的激光系统获得的测量结果进行比较。筛孔尺寸与中间主轴长度相关。在2D和3D形状测量之间注意到明显差异。破碎的颗粒，沿着现有的裂缝，发生在重建和剪切的完整的土壤，一个现象，不能观察到使用侵入性技术，如筛分析。(C)2012年，日本地质学会。Elsevier B.V.制作和主持。保留所有权利。
Particle morphologies, i.e. particle sizes and shapes, have a marked influence on the mechanical response of granular materials including soils. Until now most investigations of particle shape have been two-dimensional and size has been most often assessed using sieving. This paper makes use of recent developments in three-dimensional imaging technologies to characterize the internal features of a soil in 3D including quantification of particle morphology. The soil investigated was Reigate sand (from Southeast England), a geologically old sand, which in its intact state exhibits significant interlocking amongst the constituent grains. Intact and reconstituted specimens having similar densities were tested under triaxial compression. The specimens were impregnated with an epoxy resin at three different stages of shear deformation and small cores from each specimen were scanned using X-ray micro-tomography. Different systems and scanning parameters were explored in order to obtain 3D, high-resolution, images with a voxel size of 5 mu m (0.018 x d(50)). The morphology measurements were compared with sieve data and measurements obtained using a 2D, image based, laser system. The sieve size is shown to correlate well with the intermediate principal axis length. Clear differences are noted between the 2D and 3D shape measurements. Breakage of fractured grains, along existing fissures, occurs both during reconstitution and shearing of the intact soil, a phenomenon that cannot be observed using invasive techniques such as sieve analysis. (C) 2012 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.