Ardaman & Associates, Inc. provided geotechnical engineering services for this 14-story residential complex in Miami-Dade County, and implemented an innovative jet-grouting process to economically improve the underlying soils, allowing for a less expensive shallow foundation alternative.

The Intown condominium development project is a 320 unit residential building with two 14-story towers located in the Little Havana section of Miami-Dade County. The post tensioned concrete structures create significant column loads which are problematic for foundation design in this area. Shallow cemented limestone underlain by weak limestone and very loose sand presents the possibility that shallow footing foundations could possibly “punch out” through the shallow limestone creating excessive settlements. Typically, buildings such as the Intown structure are supported on pile foundations extended 60 or more feet deep.

Instead of using piles, Ardaman engineers recommended a program to jet-grout the weak underlying soils. This process is an in-place soil treatment and improvement technology that blends the existing soil with cementitious material to create a combined cemented material with greater strength and lower compressibility than the natural soil. Further, jet-grouting does not create vibrations that could damage adjacent structures. In this case the jet-grouting process allowed design of typical shallow footings design for an allowable soil pressure of 8,000 pounds per square foot.

Ardaman also provided quality assurance inspection and testing of the jet-grouting process as well as testing of concrete and soils, and inspection of post-tensioned concrete structural elements.