Accuracy of relative density measurements

Even if the concept of relative density of sands is widely used in practice, the precision with which this soil characteristic is determined has not been really appraised. The aim of this Paper is to evaluate the different errors affecting Dr and to examine the consequences of these errors on the use of the relative density concept in design. It is shown that the resulting error in the measurement of Dr is never negligible and can be very large in the case of the in situ determination of this characteristic. Following these observations, the validity of the well-known relationships between the standard penetration index and the properties of natural sands was investigated and proved to be questionable. Further, it is contended that Dr cannot be used as a quantitative parameter but should be considered only qualitatively to characterize a state of compactness of a soil deposit. Alors meme que le concept de densite relative des sables est largement utilise dans la pratique, la precision avec laquelle cette ...