Well-graded sediment refers to a sediment deposit that contains a wide range of particle sizes, often resulting in a dense, tightly packed structure. Well-graded sediments are significant in engineering geology and sedimentology for understanding the stability of sediments, the processes of sediment transport, and the design of foundations and embankments.
Source Holtz, R. D., Kovacs, W. D., & Sheahan, T. C. (2011). “An Introduction to Geotechnical Engineering.” Prentice Hall.