The influence of various end restraints and grain shape on the cyclic undrained behaviour of granular materials

ABSTRACT The paper describes the effect of the various ends restraints on the cyclic liquefaction potential of Karlsruhe fine sand and examines the influence of grain shape and gradation on the cyclic liquefaction susceptibility of granular materials. To assess the influence of grain shape and gradation, three materials with same mean size but two different gradations were considered. Different scenarios were considered including the influence of differing sizes of the porous discs at end platens, influence of sample size ratio at similar diameter and varying membrane thickness. Additionally, the influence of using end lubrication or filter papers is investigated. The results reflect a pronounced effect of the liquefaction resistance of KFS using porous discs with a larger diameter, where a significant increase in the number of cycles to initial liquefaction was noted. Furthermore, initial liquefaction resistance for angular/sub-angular materials reduced with increasing gradation. In contrast, it remained relatively unchanged for round materials.