Submitting Campus
Daytona Beach
Department
Civil Engineering
Document Type
Article
Publication/Presentation Date
2025
Abstract/Description
Many geotechnical analyses, including slope stability, involve unsaturated soils or soils in thevadose zone. Undrained loading happens when the increase in driving forces occurs quicker thanthe ability of the soil to dissipate its pore-water pressure (PWP). During undrained loading forcompacted clay embankments, in which the material is typically unsaturated, it has beenestablished that the increase in shear strength caused by an increase in confining pressure is largerthan the reduction in shear strength due to a decrease in matric suction. This concept is not wellestablished in engineering practice because the conventional understanding is that the strength ofunsaturated soils is larger than that of saturated soils due to suction. Air compresses under theapplication of total stress loading, even in undrained conditions, which leads to an increase in thedegree of saturation because of a decrease in the void ratio, and hence, the decrease in matricsuction. On the other hand, infiltration and evaporation of water create downward and upward flowwithin the embankment, respectively; this flow affects the distribution of PWP. In addition, thelevel of drying, i.e., how low the moisture content is of the soil during a drying cycle, affects thevolumetric change during the following wetting cycles. This paper explores the above processesand their effect on the estimation of the undrained shear strength of compacted clay embankmentsunder the expected climate change and extreme cycles of wetting and drying. An unsaturatedtriaxial testing program is proposed to further confirm the above.
DOI
https://ascelibrary.org/doi/epdf/10.1061/9780784486511.016
Sponsorship/Conference/Institution
Geo-Extreme 2025 / American Society of Civil Engineers
Location
Long Beach, CA
Paper Number
GSP 371 148
Number of Pages
6
Scholarly Commons Citation
Considerations of Undrained Behavior of Compacted Clay Embankments under Extreme Wetting-Drying Cycles Ghada Ellithy, Ph.D., P.E.; and John F. Peters, Ph.D., P.E. Geo-Extreme 2025 : Civil Infrastructure, Geomaterials, and Case Histories.
