Crushing of non-cohesive Soil Grains Under Dynamic Loading

Dynamic impact loading may cause gradual crushing of soil grains, especially when soil grains are characterised by weak strength or when the geologic history of the soil has influenced on material fatigue. The aim of the work is to identify the soil crushability during dynamic compaction, as well as the effect of a gradual grain crumbling on changes of the maximum dry density and the uniformity coefficient. All tests were performed for genetically different non-cohesive soils from various Polish areas. In Pleistocene river sands and in the sea sands - repeated compaction does not improve the coefficient of uniformity and does not result in significant changes in the maximum dry density. In the river sands from Holocene alluvial deposits, multiple compaction causes a significant increase in value of ρdmax. In glaciofluvial sands and gravel multiple compaction increases the maximum dry density and uniformity coefficient of compacted soil. The monomineralic soils was characterised by values of CU < 3.0, and the polymineralic soils - by values of CU ≥ 3.0.