SANDY RIVER LANDSLIDES

  • Project Location:
    • Chesterville, ME
    • Farmington, ME
    • Norridgewock, ME
  • Services Provided:
    • Geotechnical design and consulting for landslides along the Sandy River in the towns of Chesterville, Farmington, and Norridgewock, ME
    • Worked collaboratively with municipalities and emergency management agencies
  • Project Summary:
    • Chesterville Landslide. May 2010 – slope failure 30 feet high and 250 feet long with damage to George Thomas Road
    • Farmington Landslide. August 2011- slope failure 40 feet high and 300 feet long with damage to the slope adjacent to Whittier Road 
    • Norridgewock Landslide. March 2010 – slope failure 25 feet high and tension cracks extending for 70 feet along Sandy River Road indicating potential for further slide activity 
  • Project Challenges / Innovation:
    • Chesterville Landslide
      • The geotechnical investigation determined that the presence of soft, deep marine clay, combined with the height and steepness of the existing fill beneath the road, contributed to the slope failure
      • Based on the potential for further slide activity and cost for remediation, an alternative route to bypass the slope failure and roadway was selected
    • Farmington Landslide
      • The geotechnical investigation determined that the presence of loose, deep alluvial silts and sands, combined with soil scour caused by tropical storm Irene to over-steepen the riverbank, ultimately causing the landslide
      • With the assistance of federal funding, the project was stabilized using a rootwad log system (see photo)
    • Norridgewock Landslide
      • The geotechnical investigation determined that the landslide was caused by the presence of thick, over-steepened, loose granular fill overlying marine clay and alluvial silts and sands
      • Remediation included slope regrading to flatter, more stable conditions, a relocation (offset) for Sandy River Road, and riprap scour protection
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