Southwestern United States

Retaining Wall Failure Investigation


Shortly after the site was developed, a terraced, mechanically stabilized earth (MSE) wall failed. The MSE wall, with heights up to 63 ft tall, consisted of precast concrete facing panels and soil backfill interlayered with geogrid reinforcement. SGH investigated the failures’ causes and assisted the owner in evaluating repair options.

Highlights of our investigation include the following:

  • Reviewed design and construction documents, manufacturer’s literature, reference standards, building codes, and expert reports
  • Visited the site to document post-failure conditions
  • Developed and implemented field and laboratory investigations, including locating and making observations at test pits, detecting leaks in adjacent pressurized water-bearing utilities, and testing soils in the area
  • Performed a microscopic examination of a failed 2 in. dia. buried polyvinyl chloride irrigation line in our laboratory
  • Assessed the effects of soil type, relative compaction, moisture content, and shear strength on the wall failures
  • Analyzed the stability of the as-designed and as-built wall configuration
  • Developed a detailed sequence of events, including construction activities and weather to help identify factors contributing to the failures
  • Evaluated repair options for the MSE wall and provided recommendations for buried utility repairs

Project Summary



Completion Date
Failure Investigation
Structures | Advanced Analysis | Applied Science & Research
Specialized Capabilities
Repair & Strengthening | Geotechnical | Failure Analysis | Microscopy

Key team members

Scott DiFiore
Scott DiFiore
Heavy Civil Division Head, Boston
Bryan Strohman
Bryan Strohman