CORRELATION BETWEEN RELATIVE DENSITY AND SPT VALUES OF MINI PENETROMETER

Abstract

The concept ofretative density gives a practically useful measure of compactness of cohesionless soils. The compact ive characteristics of cohesi onl ess soils and the related properties of such soils are dependent on factors like grain size distribution and shape of individual particles. Relative density is also affected by these factors and serves as a parameter to correlate properties of soils. Various soil properties, such as penetration resistance, compressibility, compaction friction angle, permeability and California bearing ratio are found to have simple relationship with relative density. In the present study a correlation between relative density & mini SPT values has been devel-oped by carrying out exhaustive laboratory tests at different relative densities & different overbur-den pressures. The intensity of overburden pressure used in the present investigation were taken as 0, 20, 40, 80, 100, 160, 200, 240 & 280 klgtm' and relative density were taken as 3.94, 16.73, 39.29, 67.4 & 73.68 percent. Curves & equations have been developed to apply the correction due to overburden pressure on observed mini SAT values, taking as standard overburden pressure of 100 Me. The verfication is also made with supporting field tests.