Research article

THE IMPACT OF COARSE FRAGMENT CHARACTERISTICS ON COMPACTION BEHAVIOUR OF FINE GRAINED SOILS

Shayma M. RaJab1 and Tariq H. Karim2

Online First: November 30, 2022


A study was initiated to study the impact of soil rock content, rock size and rock strength on the compaction characteristics of two base soils. The treatment combinations encompassed two base soils (T1=silty clay and T2 =silty clay loam); rock strength (R1= 17.6, R2= 67.4 and R3= 119 MPa); rock size (S1=4.75 – 9.5 mm and S2 = 9.5 – 20 mm) and rock content (L1=0%; L2=5 %; L3 = 12.5%, L4=25%%; L5 = 37.5% and L6 =50%). The results indicated that the maximum dry density (MDD) of the soil rock mixture (SRM) increased linearly with an increase in soil rock content under most of the treatment combinations. Higher rock strength contributed to higher MDD, but the rock size didn’t exhibit an obvious effect. It was also noticed MDD of the SRM was lower than that of the SRM under ideal condition. Additionally, it was observed that the deviation coefficient achieved the peak value when the rock content is 25%. Multivariate regression analysis revealed that the combination of clay content, rock size, rock strength and soil rock content accounted for more than 80% of MDD of the SRM, with mean absolute error of 0.037.

Keywords

Soil rock mixture, compaction characteristics, coarse grain interference crushing behavior