Settlement Behavior of Compacted Soils Containing a Small Amount of Organic Matter

The settlement behavior of compacted inorganic soils containing a small amount of organic matter is presented in this paper. The settlement behavior was studied using one-dimensional consolidation tests. Two assumptions were established regarding the decomposition of organic matter: (1) The organic matter can decompose completely and transform into liquid, and (2) The organic matter can decompose completely and transform into gas. Based on these assumptions, weight-volume relationships were developed and consolidation tests were conducted to study the settlement behavior of soil after the decomposition of organic matter into water and air. The results of these tests were utilized for settlement analysis of slab on grade supported on inorganic soils containing a small amount of organic matter. The results of this study indicate that soils containing a small amount of organic matter exhibit one-dimensional consolidation behavior similar to inorganic soils and conventional laboratory testing procedures provide a reasonable approach to study the effect of decomposition of organic matter on the settlement behavior of inorganic soils.