Edinburgh Napier University

  Liquefaction in soils is a detrimental phenomenon. Microscale behaviours and their influence on the macroscale response during and after the onset of liquefaction are not well understood. In particular, how contact behaviours effect macroscale properties such as gains in shear strength following the onset of liquefaction. Soil characteristics such as particle size distribution (PSD) are known to have important roles in determining a soils susceptibility to liquefaction. In this study, Discrete Element Simulations (DEM) are undertaken on soils with different PSDs to investigate how contacts at the microscale are influenced by PSD and how this influences the macroscale response. Consideration is given to these behaviours before and after the onset of liquefaction to gain insight into post-liquefaction strength behaviour. Using grading entropy coordinates, it is suggested that the PSD plays a key role in a soils ability to resist liquefaction. Larger grains appear to provide greater stability and an ability gain interparticle contacts post-liquefaction. This greater stability is suggested to come from the grain structure resisting being broken and remade during liquefaction, manifesting in greater isotropy throughout loading. Whereas soils with smaller PSDs are more prone to having their grain structure broken and remade, enabling them to become significantly more anisotropic, this appears to inhibit the ability to regain interparticle contacts.