Quality, Service & Commitment


  • 26 Oct 2017

    INTERRA To Host Ribbon Cutting With Bolingbrook Mayor Celebrating Going Green

  • 21 Jul 2017

    Recipient Of Service Award Thanks INTERRA for Engineering Support With Jane Byrne Circle Interchange

  • 15 Mar 2017

    INTERRA, Inc. Full-Time Field Technician Openings in Franklin, WI

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Laboratory Certifications

  • IL & WI State DOTs
  • ASTM


Firm Certifications

  • DBE with IDOT
  • MBE with City of Chicago

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Chicago O’Hare Airport, Terminal 6 Project: “We would like to extend our appreciation to you and all of your employees who worked on the Terminal 6 Project.  All work was performed professionally, accurately and thoroughly. Your commitment to quality and …

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Sheridan Road Improvements; Evanston, IL

INTERRA Services

  Geotechnical subsurface soil exploration field inspection and testing

  Pavement section core samples

  Laboratory testing:  moisture content, pocket penetrometer tests, unit weight, Atterberg limits, sieve analysis, unconfined compressive strength, and bearing ratios

Project Summary

INTERRA’s scope of work for its field activities consisted of a subsurface soil exploration for the reconstruction of Sheridan Road between Ridge Avenue & South Boulevard, in Evanston, Illinois.  The approximate length of the reconstructed road was 3.5 miles with a total of 35 boreholes (7.5 feet depth each) completed for this project.  Soil borings were spaced at an interval of about 500 feet.  The borings were staggered so that alternate borings would be drilled on northbound and southbound lanes.  In addition, 8 core samples of the existing pavement section were obtained to evaluate the condition of the existing pavement and sub-base.

INTERRA’s scope of laboratory work for this project consisted of performing Moisture Content and pocket penetrometer tests on all recovered cohesive soil samples.  In addition, testing of selected undisturbed samples for Moisture Content, Unit Weight, Atterberg Limits, Sieve Analysis (Hydrometer) and Unconfined Compressive Strength and Illinois Bearing Ratio Tests on 4 bulk samples from the roadway areas was also completed in the scope of work.  Maximum Specific Gravity, Bulk Specific Gravity, Asphalt Content and Core Thickness tests were performed on asphalt cores.   Compressive strength testing was performed on one concrete base core.

Because of our work on this project and others completed throughout this municipality, INTERRA has established a long-term partnership with the City of Evanston, Illinois and its various general contractors.  As a result, INTERRA has provided its expertise, experience, reliable and quick turnaround laboratory results, and practical solutions through a wide variety of services.