The Effect of Compaction Effort on Shear Strength Parameters of Low/High Plasticity Clay Soils

Abstract

This paper investigates the effect of compaction effort on shear strength parameters of clay. Four clayey soils, two with high plasticity and two with low plasticity were used in this study. The initial physical properties of the clay such as gradation, optimum moisture content, maximum dry density, and Atterberg limits were determined in accordance with American Standard for Testing and Materials (ASTM) standard procedures. All soil specimens were remolded at five different compaction levels at three different water contents: dry, optimum and wet conditions. Empirical formulae were suggested to obtain optimum moisture content and maximum dry unit weight at an energy level utilizing the results obtained from the standard Proctor test. The shear strength parameters of the prepared specimens were determined using direct shear test. Another set of empirical formulae were also suggested to obtain the cohesion and friction angle at an energy level utilizing the cohesion and friction angle obtained from direct shear test at maximum dry unit weight and optimum moisture content from standard Proctor test.