Rheological properties of some marine muds dredged from China coasts

Abstract

This is an experimental study that aims to examine the rheological response of natural muds under steady simple shear, using a controlled-shear-stress system. Natural estuarine muds dredged from Haihe River in Tianjin and Mazhou Island near Shenzhen are tested. Experimental data at low shear rates are obtained and analyzed based on the Bingham and power-law models. The applicability of these two models in different ranges of shear rate is compared. It is found that the Bingham model does not provide a satisfactory description of the shear-thinning behavior of the muds at very low shear rates. The density dependence of the rheological parameters in terms of the Bingham and power-law models is also examined. On relating the rheological behavior to the particle size distribution, it is pointed out that the presence of coarse particles with a mean diameter d > 0.1 mm may lead to dislocation of particles in the internal structure, thereby causing the yield stress and viscosity of the material to decrease. Copyright © 2010 by The International Society of Offshore and Polar Engineers (ISOPE).