A laboratory study was performed to investigate the correlationsbetween the clegg impact value (civ), california bearing ratio (cbr), and cone index (ci). Civ values were obtained using a clegg impact soil tester. A prototype automated cone penetrometer (30 deg rightcircular cone with base diameter of 5/8 in.) Was used to develop cidata. The correlation data were obtained using soil specimens constructed in a 19.25-In.-Diameter by 22-in.-Deep laboratory compaction mold. Three levels of soil type, moisture content, and compactive effort were used to develop soils with a range of cbr from approximately 1 to 30. Satisfactory simple linear correlation (adjusted r-squared values ranged from 0.94 To 0.98) Were developed between civ values and the square root of cbr. Correlations between civ and cbr were less satisfactory with adjusted r-squared values between 0.63 And 0.75. Useful correlations (adjusted r-squared values ranged from 0.58 To 0.82) Were also developed between the ci values at 2 and 6 in. Ofpenetration depth and civ. All statistical relationships were significant at an alpha level of 0.0005. This paper appears in transportation research record no. 1309, Geotechnical engineering 1991.
Abstract