The evaluation of triggering potential and induced deformations is crucial for liquefaction assessment of geosystems constructed on, or comprised of, coarse-grained soils. A series of cyclic constant volume direct simple shear (DSS) tests were simulated using the discrete element method (DEM) to investigate the influence of gradation on the pre- and post-liquefaction behavior of coarse-grained soils, including the resistance to initial liquefaction, accumulation of shear strains, and evolution of fabric. The DEM simulations were conducted on isotropically consolidated cubical specimens composed of non-spherical particles with a coefficient of uniformity (CU) C U ) range between 1.9 and 6.4. At similar relative densities, specimens with broader gradations yield lower liquefaction triggering resistance than poorly-graded specimens. However, at the same initial state parameter, the more broadly-graded specimens have higher liquefaction triggering resistance. Regardless of the parameter of state used for comparison, the specimens with broader gradation accumulate post-triggering shear strains at smaller rates than the poorly-graded specimens. The presence of coarser particles in the broadly-graded specimens promotes stable packing and enhanced interlocking by forming a substantially large number of contacts, which limits the particle movement and produces lower post-liquefaction strain accumulation. In contrast, the finer particles contribute minimally to the overall specimen stability. Additionally, wider gradations increase the anisotropy in the contact forces, with the strong forces aligning in the major principal stress direction and the weak forces providing resistance against buckling. These insights contribute to a better understanding of the pre- and post-liquefaction triggering behavior in granular soils and the implication for the design of resilient infrastructure built on, or comprised of, coarse-grained broadly-graded soils.

来源平台：COMPUTERS AND GEOTECHNICS