Project Summary: 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 the Mississippi Department of Transportation (MDOT). The objective of the current study is to evaluate long term performance of highway slopes on Yazoo clay in field condition and connecting the gap between electrical resistivity imaging (ERI), ground penetration radar (GPR) for slope failure investigation such as an identifying failed area and failure depth, and evaluating soil parameters such as moisture content. 

Six repaired highway slopes will be monitored to collect data on in-situ moisture content, matric suction, and temperature variation, and deformation to evaluate long term performance. Besides field monitoring, advanced numerical modeling using the Finite Element Method (FEM) will be conducted to evaluate the field performance data. Besides, Geophysical testing such as ERI and GPR will be conducted in the landslide sites around Mississippi to evaluate the slope movement and advance the site investigation technique. LiDAR imaging using a handheld device and Aerial survey using a drone (photogrammetry) will be conducted on each slope to monitor the surficial deformation. The field monitoring data and FEM analysis results will be combined to evaluate the performance of the repaired slope.

ERI and GPR test results will be compared with slope movement from inclinometer data and surface movement data from LiDAR/Aerial Survey imaging and field instrumentation results. This dataset will be analyzed in the multivariate statistical environment to connect electrical resistivity with the geotechnical parameters of soil. Finally, an advanced landslide investigation protocol for MDOT will be developed, and a slope rating mechanism will be introduced. This protocol will use to increase reliability and confidence level as well as reducing the cost of landslide repair for MDOT.