摘要: |
Slope failures are frequent in highway embankments as well as in waterway infrastructures (levees) on expansive Yazoo clay in Mississippi which cause significant maintenance problems and require millions of state and federal dollars to fix it. After construction, the strength of the high plastic clay degrades with time due to the seasonal temperature and moisture variation, which is one of the major factor of slope failure. However, no study is available on the strength reduction of Yazoo clay soil. The current study intent to investigate the repeated drop in the shear
strength of the Yazoo clay soil with wet-dry cycles which cause slope failure. Highly plastic Yazoo clay soil samples will be collected from slope sites to investigate the soil mechanical properties. The high plastic Yazoo clay samples will be tested at the laboratory to investigate the effect of wetting and drying cycles on the degradation of the shear strength. An advanced numerical modeling using Finite Element Method
will also be conducted to evaluate the effect of different frequency and duration of rainfall (based on historical rainfall data of Mississippi) on the water intrusion and corresponding change in the factor of safety of the highway slope. The laboratory study and numerical analysis results will be combined to investigate the failure mechanism of slopes in highway embankment and waterway levees in Mississippi
and develop a model that connects the wet-dry cycles and rainfall volume with the factor of safety of slope. The developed model will improve the design of the slopes in highway embankment and waterway levees, and will save the maintenance dollars. |