Three-dimensional Microstructure Characterization of Loess from South Jingyang Plateau, China = Three-dimensional Microstructure Characterization of Loess from South Jingyang Plateau, China

다국어 초록 (Multilingual Abstract)

The loess collapsibility and permeability are primarily controlled by the microstructure. This microstructural investigation of loess (L1 and S2) on the Loess Plateau in China is based on X-ray micro-computed tomography. The 3D microstructural features of particles and pores are quantitatively studied by analyzing statistical parameters. A total of 92% of the particles have sphericity that lies in the range between 0.5 and 0.9, the aspect ratio of 93% particles is between 0.3-0.7. 67% of the particles are oriented between 0°- 45° (the angle between the long axis of the grain and the horizontal plane). Loess exhibits complex pore structures and obvious anisotropy, as reflected by dense networks, wide pore size ranges and different pore throat radii and frequencies at different dip angles. From L1 to S2, the structure tends to become more compact, the pore size tends to decrease, and the connectivity tends to weaken. Pore structure, which provides space for water movement, has a profound influence on the mechanical behavior of soil, and the relationship between permeability and pore structure is discussed. The results demonstrate the positive role that the pore (>13 μm) proportion, pore connectivity and pore throat radius play in permeability. Both the pore throat radius and the permeability coefficient are greater in the vertical direction than in the horizontal direction, implying a large pore throat has a greater effect on water migration than that of multiple small pore throats.