Abstract:
This project case study involves a landslide located along SR-108 near the town of Whitwell, Marion Co, Tennessee. The Tennessee Department of Transportation engaged consultants for site characterization and engineering evaluation which resulted in the selected stabilization method, an anchored soldier pile (ASP) wall. Landslides along this stretch of SR?108 have been documented since at least the early 1970’s, particularly at the contact between the Warren Point Sandstone unit of the Gizzard Formation and the underlying weaker, shale-rich Pennington Formation. TODT implemented several temporary treatments over the years to mitigate the creeping landslide, including a 1992 shift of the alignment to place the roadway closer to the uphill sandstone cut and away from the downhill slope, and drainage improvements. However, recent increases in the rate of movement made it clear that a permanent solution was needed.Â
A multi-phase field investigation was performed included soil/rock drilling, installation of standpipe piezometers and inclinometers, and a geophysical investigation including electrical resistivity, SASW and MASW methods. Design of the ASP wall was based on determining the amount of tieback anchor resistance needed to meet the target global stability factor of safety. The design also includes resistance provided by the embedded portion of the soldier piles based on the method described in the recent DFI-funded research report “Guidance for Factoring Structural Resistance in Stability Analysis.â€
This presentation will include an overview of the project and field investigation, followed by a summary of the ASP wall design methodology and proposed wall schematic.  Â