Sedimentation of a Clay-Water System

4 Compressibility and Permeability of Fine-Grained Marine Sediments 8.4.1 Sedimentation of a Clay-Water System 

Resvilts of regression analyses, r is the linear correlation coefficient, (a) Liquid Umit and plastic limit, (b) Plasticity index. Note increase in plasticity (Zp has positive slope), (c) Grain-specific gravity. (After Booth, J.S., and Dahl, A.G., Marine Geotech., 6,281-29 1986. Reprinted by permission of Taylor Francis Group.) 

The material between lines AB and CB is a suspension which is essentially a heavy fluid. The material below line CB is a soil which is consolidating under its own weight. At times greater than t2, the material is a traditional soil-water system consolidating under its own weight. 

The times Zj and Z2 as well as the shape of the curves AB and CB will depend upon a variety of factors. Some of these factors are the nature of the soil particles, the salt concentration of the mixture, the initial water content Wq, the impimties in the mixture, the temperature environment, and so on. For example, it has been shown (Imai, 1981) that for kaolins and silts, the flocculation time is essentially 0. Furthermore, AB and CB are then straight lines. This simplification does not apply for more active clay minerals such as illites or smectites. 

Qualitative Summary of Selected Studies on the Relationship between Organic Matter and Sediments or Soils 

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