Performance Evaluation of Highway Slopes on Yazoo Clay

Slope failures are frequent in highway embankments on expansive Yazoo clay in Mississippi due to the rainfall and climatic variation and cause maintenance problems to Mississippi Department of Transportation (MDOT). The objective of the current study is to investigate the infiltration behavior of the slope on expansive Yazoo clay during rainfall using field monitoring and evaluate its impact on safety of the slope. Six repaired highway slopes will be instrumented comprehensively to monitor the moisture, matric suction, and temperature variation, and monitoring the deformation using vertical inclinometers and topographic survey. Besides field monitoring, advanced numerical modeling using Finite Element Method (FEM) will 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 factor of safety of the highway slope. Finally, the field monitoring data and FEM analysis results will be combined together to evaluate the performance of the repaired slope.