Mitchell Interchange MSE Walls and Embankments, Milwaukee, WI


Project Description:

This major project included a widening and realignment of Interstate 94 in Milwaukee County, Wisconsin. We presented a value-engineering alternative to limit the use of expensive lightweight fill.


The typical conditions were ten to 20 feet of mixed sand and clay fill that contained organics and rubble, followed by stiff native clay.  In some wall sections up to 24 feet of Weight of Hammer peat and organic clay were encountered during construction.  We were able to adjust the design to accommodate the very poor organic soil conditions.


We worked with Walsh Construction and Milwaukee Transportation Partners to design  ground improvement solutions to limit the use of expensive lightweight fill.  We used the Geopier GP3TM system which enabled the installer, Foundation Service Corporation, to identify changes in soil conditions by visual confirmation of the drill spoils.

The Geopier GP3 system provided cost savings over lightweight fill and enabled Walsh Construction to expedite the wall erection schedule.  Foundation Service Corporation installed 1,520 GP3 elements in 38 days, which included the time to adjust to the unanticipated deep organic soils.

Project Team

Ground Improvement Designer: Ground Improvement Engineering
Structural Engineer: Milwaukee Transportation Partners
Geotechnical Engineer:  Milwaukee Transportation Partners
General Contractor/Developer: Walsh Construction
Geopier GP3 Installer: Foundation Service Corporation, Hudson, Iowa