Triaxial Test on Soil - Important Insights for Stress-Controlled and Strain-Controlled Test

Abstract

Triaxial testing of soils is carried out under various loading methods to simulate field loading conditions or to analyze the fundamental behavior of soil material. The objective of this paper is to review the triaxial testing of soil under stress control and strain control loading mode. The triaxial shear test simulates 3- dimensional stress condition including pore water pressure is an identical condition that occurred in situ on soil specimen; this is the advantage of the triaxial test over other shear tests on soil. The triaxial test apparatus, procedures, and sample preparation is explained in brief. The analysis of results over drainage conditions and shearing phase is incorporated. The modern triaxial tests contain thorough control over test setup and accurate results are determined which makes the triaxial test versatile and used for research in geotechnical engineering. The different loading modes are used to simulate the field stress, strain condition and to understand the response of the soil by many researchers. They analyzed test results of the same soil specimen tested under both modes of loading (i.e., stress and strain-controlled) will focus on parameters like progressive failure, peak strength, and residual strength behavior of soil. Monotonic loading under strain control test gives post-peak behavior of soil necessary to understand the progressive failure. Similarly, the stress-controlled test is useful to study timedependent deformation in clay. The comprehensive study presented here for the stress and strain control triaxial test and finally, it focuses on recent advancement of technologies in respective loading modes.