Acta Scientiarum Polonorum

Abstract: The impact of non-cohesive soil graining with bimodal grain-size distribution on its compaction was analyzed in the paper. Ability to compaction of non-cohesive soils is usually estimated on the basis of coefficient of uniformity (CU) or jointly two graining coefficients − CU and coefficient of curvature (CC). In the case of soils with discontinuous grain-size distribution values of coefficient of curvature CC are more often lower than 0.5. Those soils are classified outside the well-compacted soils, as poorly graded soils. Results of the analyses carried out with the index of compaction curve shape IC indicate that soils with discontinuous grain-size distribution – despite the low values of coefficient of curvature (CC) – can be considered as well-compacted soils.