USH 51-STH 29 Reconstruction

Location

Wausau, Wisconsin

 

Client

Wisconsin Department of Transportation District 4

 

Services provided

Geotechnical engineering

Stormwater management

Permitting

 

Project overview

The six-mile I-39 reconstruction project included expanding the existing corridor from four to six lanes and major reconstruction of the two STH 29 freeway interchanges and five local urban interchanges. The project also required construction of multiple storm water detention and wetland systems.

 

Approach

STS was selected as the Geotechnical Engineering Consultant and Drilling Contractor for this project. STS evaluated the regional and local geologic history and performed nearly 200 soil borings from depths of 15 feet to over 100 feet over three project phases. We also installed ground water observation wells for hydrologic studies and excavated test pits for constructability studies.

 

STS completed a pedological evaluation, embankment stability and settlement analyses and provided design and construction recommendations for segmental and MSE retaining walls, bridge foundations, storm water retention systems and embankment construction over soft soils.

 

The soil conditions ranged from shallow bedrock and residual overburden soils to relatively deep glacial outwash deposits, so STS investigated possible borrow sources and detention ponds. Additional responsibilities included contacting Digger’s Hotline to coordinate and identify the locations of any underground obstructions, obtaining necessary permits to traverse across private property, informing local units of government, performing necessary traffic control and implementing a safety program.

 

Client benefits

• STS provided consistent geotechnical design recommendations and a single point-of-contact.
• Our knowledge of the geologic and depositional history and the man-made developments along the corridor gave STS the big picture, allowing the designers to understand what general conditions could be expected along the corridor.
• STS attended monthly design progress meetings to address questions from the various design consultants.
• Throughout the project, STS used an FTP site to upload interim Geotechnical Reports summarizing exploration data and recommendations to-date, providing the designers with one report for all of the project’s geotechnical information.