Experimental investigations to select stabilization methods to mitigate embankment desiccation cracks in order to reduce slope failures

Repeated weathering (wetting-drying) cycles produce desiccation cracking within plastic clay fill materials of earthfill embankment dams. This process can permit the fill materials to become saturated which can lead to shallow and medium slope failures ("skin slides"). It is therefore critical to mitigate volumetric change (shrink-swell) behavior of these fill soils to reduce their susceptibility to skin slides.; Grapevine Dam and Joe Pool Dam, two north-central Texas earthfill embankment dams, have experienced prolific, recurrent skin slides, and were selected as suitable test sites for the research project. Representative soil samples were collected from these dams and transported to the UTA geotechnical laboratory. The control soils were mixed with a total of ten treatment types to evaluate their effects on controlling shrink-swell and strength behavior of soils. Treatments evaluated include polypropylene fibers at dosages of 0.15%, 0.30%, and 0.40%, hydrated lime at dosages of 4% and 8%, combinations of these two stabilizer types, and compost treatment at 20%. Based on soil property improvements determined through analyses of the laboratory testing data, four to five treatment types and compaction moisture contents were selected for each test site and recommended for further evaluation through construction of on-site embankment test sections.