Experimental Study on the Effect of Moisture Content on Shear Strength of Unsaturated Silty Clay

Most soils in the natural state are unsaturated. At present, the theoretical formulas for the shear strength of unsaturated soils are difficult to apply in engineering practice due to the difficulty in obtaining the physical parameters. While one of the factors determining the fundamental physical indices of soils is moisture content, is convenient to be obtained. Based on the indoor consolidation undrained shear test, analysis was done on how changing moisture contents and confining pressure affected the strength and deformation traits of remolded silty clay. Results show that the shear strength is affected by the combined effect of moisture content and confining pressure, the increase of confining pressure can significantly improve the shear strength of soil. Under the condition that the moisture content is maintained constant, the perimeter pressure has a positive relationship with the percentage increase in shear strength of unsaturated chalky clay. So, the formula for the total stress strength of unsaturated soil with the moisture content as the independent variable is established by curve fitting. The findings of this study can serve as a valuable guide for estimating the shear strength produced by the local change in groundwater level in silty clay layers. © 2023 School of Science, IHU. All rights reserved.