Development of correlation between dynamic cone resistance and relative density of various sands

Abstract

As a measure of control of quality of a landfill project, sand cone test is usually used. Sand cone method in its nature is gcnerally cxpensivc in cost and cumbcrsome to do and done after completion of compaction of every singlc laycr. The prcsent study was aimed to develop an alternative indirect mcthod that can be suggested to use to determine relative density of a sand deposit in an easier manner. This study was carricd out in three stagcs. In the lirst stage thc air pluviation mcthod was calibrated to know the height of fall and hole diamctcr of sand discharging container for a desired relative density of specific sand. In the sccond stage sand deposits of different relative densities were prepared in calibration chamber and both Dynamic Probing Light (DPL) and Dynamic Cone Penctrometer (DCI') tests were performed on the prepared sand dcposit. Correlation bctween N 10 (Number of blows rcquired for 10 cm penctration of con c) and relative density was made from the test result in calibration chamber. DPL and DCI' tests were performcd in two dredge fill sites to verifY the correlations. Good correlation between relative density and N 10 was found for Sylhct sand and Jamuna sand using DCI' and DI'L. The correlation was successfully verified in two dredge fill sites. Performance of DPL was found to be better than DCI' in determining relative density of in situ sand. It was found that the larger the particle size grcater bc the resistance to penetration for a fixcd rclativc density of sand. After normalization ofNIO by dividing NIO with square root of mean particle of size of sand, a gencralized corrclation for all sands was found. Denser sand gives more resistance for a specific type of sand. Resistance of sand increases exponentially with relative density. Finally it is concluded that the proposed method (DCI' and DI'L) can bc uscd as an alternative method to determine in situ relativc density of sand deposit.