Quality, Service & Commitment


  • 08 May 2018

    IRTBA Announces INTERRA President To Serve On Green Council Board Of Directors

  • 28 Apr 2018


  • 08 Dec 2017

    INTERRA Honored With 2017 IRTBA Green Industry Achievement Award For Green Initiatives

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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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You have skilled people, a superior laboratory facility with all the equipment in excellent condition and an outstanding QC/QA program. Your certified tranined staff was knowledgeable, courteous and proactive…

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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.