County Highway Z/Thousand Islands
Nature Preserve
Kaukauna, WI

Pavement distress and slope distress of an embankment was noted along a stretch of CTH Z, parallel to the Fox River. The embankment extended from the pavement shoulder to the Fox River, was part of the 1000 Islands Nature Preserve, and included a portion of a walking trail. A subsurface exploration was performed of the embankment distress areas. It was determined that the distress was the result of a combination of factors including block sliding, circular slip failure and subsurface water concerns.

Based on the evaluation of soil conditions and causes of the embankment distress, recommendations were made which included adding a rip-rap counterweight at the toe of the existing embankment and in the Fox River, providing subsurface drainage, and repair of the existing slope conditions. Design and construction of the project involved coordination with the Wisconsin Department of Natural Resources, Corps of Engineers, Outagamie County Highway Department, 1000 Islands Nature Preserve and the City of Kaukauna.

Wittman Regional Airport
Air Traffic Control Tower,
Wisconsin Department of Transportation,
Bureau of Aeronautics
Oshkosh, WI

OMNNI’s geotechnical engineers investigated two proposed sites for the design and construction of the foundation for a new air traffic control tower at Wittman Regional Airport. The investigation was to determine subsurface soil conditions and provide recommendations for the foundation design based on significant foundation loads.

Due to the soil and water conditions encountered at the initial site, a foundation was recommended that consisted of a pile or drilled pier foundation tied to a large mat foundation. The client eventually abandoned this site and the second site was investigated. Although the sites were only a few hundred yards apart, soil conditions differed substantially enough at the second site that pile or drilled piers were not required. Relatively shallow bedrock and very stiff/dense weathered bedrock resulted in foundation recommendations that consisted of a mat foundation bearing on very dense/very stiff weathered bedrock and/or shallow bedrock.

Various Roads and Bridges

OMNNI Associates Geotechnical Engineers perform subsurface investigations for redesign/reconstruction of roads and bridges for local, county, and state agencies to determine design and construction parameters for these structures.

On road projects, subsurface investigations generally consist of shallow borings to document existing pavement sections for design of a reconstructed or rehabilitated pavement section, identify shallow subsurface soil conditions for determining design parameters based on soil conditions, define areas where unsuitable pavement subgrade soils may be encountered which may involve additional construction costs, and determine soil conditions that may affect design and construction of utilities involved in the project.

On bridge projects, subsurface investigations determine the types and depths of foundations required for bridge abutments and piers, as well as address roadway approach concerns. Bridge projects usually involve deeper borings as abutments and piers are typically supported on a deeper foundation.

Communication Arts Center
University of Wisconsin - Fox Valley
Menasha, WI

OMNNI’s Geotechnical Engineers investigated the proposed site for the University of Wisconsin – Fox Valley’s Communication Arts Center. The 33,700- square-foot facility consisted of a single-story, two-story, and auditorium height structure, including a 70-foot fly tower.

Due to the soil and water conditions at the site and because foundation loads varied based on location within the facility, the site was divided into 5 zones. Upon review of the test boring data and laboratory results, a foundation for column and wall loads in Zones 1, 2, and 3 of the proposed structure were recommended to be placed on a conventional spread footing foundation.

In zones 4 and 5, based on the subsurface conditions, large column and walls loads, and anticipated settlement for conventional spread foundations in these zones,it was recommended that foundations be constructed on a deep foundation system.  A soil modification system consisting of a grid of Geopiers ® was recommended as a viable and more cost-effective alternate to a typical driven pile foundation.

Geopiers®, consisting of larger diameter shafts drilled into the underlying softer soil layers and filled/compacted with crushed stone aggregate, were used to “stiffen” the underlying softer fat clays and to limit soil consolidation allowing for foundation construction.