Vertical and horizontal permeability measurements in organic soils

Abstract

Abstract The paper is referring to vertical and horizontal laboratory permeability measurements in soft organic soils. The estimation of anisotropic permeability in soft organic soils, as peats, requires to use a special apparatus and the knowledge of proper analysis of the test results. During loading the void ratio decreases substantially that causes the changeability of the permeability. The change of permeability during the compression is very important because of the influence of the consolidation co-efficient. Initial strain in soft organic soils appears very quickly, just after loading, and brings immediately the decrease of permeability. In most of the estimations, it is assumed that during the consolidation process the water flows just in the vertical direction. In soft organic soils, like peats, the consolidation theory should consider the changes of mechanical and physical properties in consolidation period, in both directions. The direct measurement of vertical and horizontal permeability of organic soil and the non-Darcian flow theory may be of considerable importance in estimating pore water pressure dissipation, and settlement rates in the consolidation model. In the paper, the method of investigation and the test results of the vertical and horizontal permeability are presented. The Modified Rowe Cell Set for obtaining consolidation and flow characteristics in different directions is used.