Grouted Impact® System

40+ ftinstallation depth
10+ ksftypical bearing capacity
  • Ideal for deep, soft clay and organic soil profiles
  • Rapid installation (schedule savings)
  • 20-50% savings versus deep foundations and over-excavation
  • No spoils and haul-off costs

The Geopier Grouted Impact® system takes our traditional Impact pier and adds grout to the open-graded aggregate during installation.  Grout is introduced to the system within the mandrel and mixed in place to create a high-strength grout-aggregate mix. The pier is then constructed like a traditional displacement Impact pier.  The end result is a very stiff, cemented pier element that provides confinement in weak soils and excellent settlement control for heavily-loaded structures.

Soil Type
  • Organic soils or very soft clays and silts
  • Marginal soils for heavily loaded structures

The Geopier Grouted Impact® pier installation process is essentially the same as the traditional Impact pier with the exception that grout is added to the mandrel during installation. The pier is installed by advancing a displacement mandrel through unsuitable soils to a desired design depth. Once at depth, the mandrel is withdrawn several feet to allow open-graded aggregate to flow into the annular space.  The mandrel is then redriven to create a densified 2-foot-thick lift of aggregate.  These steps are repeated up to the ground surface to create a dense column of aggregate and grout surrounded by stiffened matrix soils.

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Design Considerations

  • Ideal for organic soils, heavy loads, and/or adjacent structures
  • Foundations can be designed as conventional spread footings with bearing pressures up to 10+ ksf
  • Slabs can be constructed as conventional slab-on-grade
  • Requires a gravel pad or load transfer platform

Design Considerations

  • Generates no spoils, eliminating haul-off costs
  • Often results in 20% to 50% cost savings compared to traditional alternatives (removal and replacement and deep foundations) 
  • Rapid installation process means shorter construction schedules