Preliminary study on the mechanical behavior of clay in one-dimensional compression with DEM simulations

Abstract

The mechanical behavior and physical properties of clay are closely associated with its microstructure. Current research on the macroscopic mechanics and physical properties of clay is comprehensive and systematic. However, the microstructural variations underlying these characteristics have been predominantly examined under mercury intrusion porosimetry and scanning electron microscopy, while quantitative and systematic studies are notably limited. This research employs the discrete element method (DEM) simulation to investigate the microscopic responses of clay, simulating one-dimensional compression tests on two clay types: card-house and book-house structures. The analysis of pore size and morphology was conducted using virtual mercury intrusion porosimetry and the pore segmentation method. The clay microstructure was quantitatively characterized by parameters such as pore aspect ratio, orientation distribution, and cumulative pore volume curve. The findings demonstrate that DEM effectively replicates the fundamental mechanical behavior of clay, revealing and explaining the evolution pattern of clay pore structure during one-dimensional compression in terms of platelet alignment adjustment. This macroscopic compression is characterized by variations in pore size distribution, orientation, and aspect ratio.