Experimental Evaluation of Shear-Strength Behavior of Delhi Silt under Static Loading Conditions

Abstract

The capital city of India, Delhi, lies in the Indo-Gangetic alluvial trough. The soils of the Delhi region are known as “Delhi silt” because of the dominance of silt and, by and large, are nonplastic. The strength properties of Delhi silt, which contains either 60% or 20% sand, are experimentally evaluated with samples prepared using a slurry deposition technique in the laboratory and a stress-path triaxial system. Stress-strain-volume change and pore pressure behavior of these specimens under conventional triaxial compression (CTC) and the reduced triaxial extension (RTE) test for four values of confining pressures were measured, and strength properties are reported. These strength parameters as well as stress-strain volume change/pore pressure response were also compared with the results reported by other researchers; the observed behavior of Delhi silt is in good agreement with that of other silts reported in the literature. The study corroborated that the nature of Delhi silt is transitional, that is, it can be described by neither a sand nor a clay type of framework. All aspects of the mechanical behavior captured in this study (e.g., stress-strain volumetric response, pore pressure, and shear strength) were found to be affected by the amount of fines present in the sand and the loading conditions.