Effect of percentages of sand on the permeability of sandy clay

Abstract

The interest in research and measurement of permeability of fine grained soils at low hydraulic gradients has increased significantly in the past few years. It has been suggested that a modified triaxial cell test can be used to measure the coefficient of permeability of laboratory compacted saturated sandy clay under low hydraulic gradient. Brief comparisons have been made among several available permeability testing methods to justify this suggestion.The study focused on the flow conditions through laboratory compacted saturated sandy clay samples and the results of the tests. The triaxial permeability tests were carried out on samples to investigate the effect of medium percentages of sand on the permeability of sandy clay. The study also examined the effect of hydraulic gradient on the coefficient of permeability of the sandy clay in the laboratory under controlled conditions to acquire repeatable results. All samples were undergoing back pressure saturation to ensure that the samples had been fully saturated (B ≥ 0.95) prior to conducting permeability test. Geotechnical Digital System (GDS) equipment was introduced and used to measure amount of water flow through the sample precisely as well as to control and maintain the hydraulic gradient across the sample.