Client:
Michigan Department of Transportation

Contact:
Mr. Lex Kinter (MDOT) (248) 483-5167

Location:
Wayne County, MI

Prime Consultant:
NTH Consultants, Ltd.

Total NTH Budget:  
$600,000

Project Start:
2011

I-96 Reconstruction
Subsurface Utility Locating and CCTV Utility Inspection

Project Overview
The Michigan Department of Transportation (MDOT) reconstructed approximately eight miles of I-96, from Newburgh Street to Telegraph Road within Wayne County, Michigan.  MDOT retained the services of Parsons Brinckerhoff (PB) for developing design plans for the reconstruction project between Melvin Street and Telegraph Road, who retained NTH Consultants, Ltd. (NTH) to perform various services including subsurface utility engineering (SUE). NTH performed an investigation for the eastern four mile segment of the freeway reconstruction, which is located from Melvin Street to Telegraph Road.  

NTH, acting as a subconsultant to PB, performed geophysical investigations at various locations along the project in order to locate subsurface utilities in three dimensions, assessed the conditions of existing storm sewers, and completed other utility assessment aspects for the project. Following utility locating and condition assessments, the design team cost-effectively updated the project documents to account for our findings.

Project Approach
The utility locating consisted of SUE Quality Level A through D services. NTH initially reviewed the existing utility owner and original design plans and then field designated the known utilities using ground penetrating radar (GPR), electronic utility line locators, and other equipment. Several utility crossings, which were potentially conflicting with the proposed roadway vertical alignment, were subjected to vacuum excavation to expose the location of the utilities. PB used the results of the SUE investigation to adjust the design plans to minimize project costs and future construction conflicts.

NTH also performed closed circuit television (CCTV) sewer survey for the trunk sewer running the entire eight mile project length. The survey included a total of 82 storm reaches ranging in diameter from 60 to 90 inches. The sewer conditions were cataloged following the Pipeline Assessment Certification Program (PACP) standards and resulted in numerous areas requiring treatments including heavy cleaning, chemical grouting, relining and spot repair. The investigation and repair of the sewer saved millions of dollars and significant construction time over reconstruction of the affected sewers.

Project Results
The approximately $150 million reconstruction of I-96 was a major undertaking for MDOT, completely closing the freeway to traffic for a period of about seven months while 56 lane-miles of pavement were reconstructed and 37 bridges were replaced or rehabilitated. NTH played an important role in several aspects of the reconstruction including SUE, utility condition assessment, utility coordination, lead paint and asbestos testing, bridge footing and strut locating, geotechnical investigations, and retaining wall design, helping MDOT and the design team at PB achieve project success.