G Shear Test to Determine Shear Characteristics of Coarse Grained Soils at Low Normal Stresses

Abstract

Shear strength is one of the most important properties of soil which controls various engineering aspects of geotechnical engineering such as bearing capacity, slope stability, pile capacity, etc. Therefore the determination of shear strength of soil is prerequisite for engineering purpose. The shear behaviour of soil is influenced by various factors such as drainage, compaction, confining stresses, etc. Hence, it is necessary to analyze the shear behaviour of soil that is appropriate to the field condition. Various tests such as direct shear, ring shear, tri-axial, unconfined compressive strength tests, etc., have been developed to determine the shear strength of soil. These tests are often operated at relatively high normal stresses. As soil behaviour at low normal stress is very different from that obtained using the above tests, a new test named as Gravity shear (G-Shear) test has been developed in which shear testing of soil can be performed at low normal stresses. Direct and G shear tests have been performed on sand at relative densities of 50% and 80% at different normal stresses. Results from these tests have been analyzed to contrast the shear behaviour of soil with the normal stress.