Effects of sodium sulfate content on mechanical behavior of frozen silty sand considering concentration of saline solution

Abstract

Triaxial compressive tests were conducted on a frozen silty sand with four sodium sulfate contents (0.0%, 0.5%, 1.5%, and 2.5%) at temperature of −6 °C. The test results revealed that it is important and necessary to firstly identify whether the concentration of sodium sulfate solution in the silty sand is saturated for studying effects of the salt content on the strength and deformation characteristics. We established a function which can interconvert the concentration of the sodium sulfate solution and the sodium sulfate content in the silty sand if either one of these two variables is a known quantity. Based on this function, the saturated or unsaturated state of the concentration of sodium sulfate solution corresponding to each given sodium sulfate content in the frozen silty sand can be conveniently identified. The influence of confining pressure and sodium sulfate content on the deformation characteristics, failure mode and strength of the frozen saline silty sand were then analyzed. Keywords: Frozen silty sand, Sodium sulfate, Strength, Triaxial compressive test, Deformation characteristics