Numerical explanation of microscopic/macroscopic behavior of reliquefied sand using 3D DEM with non-spherical particles

Field investigations showed that sand experienced liquefaction history may re-liquefy and cause more severe catastrophes. Previous liquefaction history would form various fabrics that influence significantly the sand reliquefaction resistance. Although some research has focused on the macro-mechanical response of sand reliquefaction, understanding the fabric evolution during reliquefaction process from microscopic viewpoint is not sufficient. Therefore, this research aims to numerically clarify the fabric evolution of sand with different liquefaction histories using 3D DEM. The stress-induced anisotropy, cyclic shear stress ratio and shear direction were considered in element tests. Numerical test results indicated that the liquefaction history has a great influence on the stability of sand particle aggregation. Furthermore, the reliquefaction resistance of sand was found to be dominated by the distribution of contact normal, particularly the preferred orientation of contact normal. Finally, the interrelation between the mechanical behavior and the fabric anisotropy were established to reveal the microscopic mechanism of sand reliquefaction.

Automated summary

Field investigations have shown that sand with a history of liquefaction may re-liquefy and cause more severe disasters. The fabric formed during the previous liquefaction plays a significant role in influencing the sand's resistance to re-liquefaction. However, the understanding of fabric evolution during the re-liquefaction process from a microscopic viewpoint is still insufficient. This research aims to numerically study the fabric evolution of sand with different liquefaction histories using 3D DEM.