• Ground Improvement
• Illinois DOT
• Hazelwood Schools
• Wentzville
• West Memphis
• St. Peters Rec Plex
• Sheboygan Police Station
• Lange-Stegman
• Kennett
• Bluffton Ethanol
• Wheeler Center
• Earth Retention
• Metrolink
• Warrenton Copper
• MoDot
• Centrum Properties
• Pinnacle Tunnel
• Metropolitan Sewer
• Drilled Shafts
• Hwy 40 Retrofit
• Pinnacle Casino
• Eads Bridge
• Driven Pile
• MCI WorldCom
• Ameren UE
• Augercast
• Proctor & Gamble
• Micropile
• Lenzburg Bridge
• St. Louis Zoo
• Cupples Station

Service: Vibrocompaction / Vibro Stone Columns
This project involved construction of the new Community Supervision Center in Kennett, Missouri, a town located less than an hour from New Madrid, MO. With the proximity to the New Madrid Fault, liquefaction of existing loose sands and silty sands was a significant concern. A ground improvement design consisting of vibrocompaction to densify existing sands and vibro stone columns to support the structure was undertaken at the site. Soils at the site consisted of alluvial sandy clays and silts overlying loose to medium, relatively clean sand.

Approximately 970 vibro stone columns were constructed in order to improve the soft upper soil to a post-treatment bearing pressure of 2,500 pounds per square foot. At each of these locations, vibrocompaction was first used in the underlying sands to mitigate for liquefaction. Post-treatment modulus testing and borings with SPT testing were employed to verify the design parameters. Post-treatment SPT (N) blow counts in the sands were often 3 to 4 times the initial values, indicating a significant strength increase of this layer.

• Owner: Missouri Department of Corrections
• General Contractor: Brown Construction
• Geotechnical Engineer: Holcomb Foundation Engineering
• Structural Engineer: Robert Stearnes & Associates
• Ground Improvement Design/Builder: Subsurface Constructors, Inc.