For this Illinois Tollway project, INTERRA provided Phase II engineering services consisting of Geotechnical subsurface soil investigation, the preparation of Roadway Geotechnical Report (RGR) and Structural Geotechnical Report (SGR). The geotechnical investigation included drilling soil borings to depths varying from 10 to 80 feet below ground surface. All soil samples were tested in the laboratory for natural moisture content and unconfined compressive strength using a RIMAC or pocket penetrometer. Samples were tested for organic content, grainsize analysis, Atterberg limits, unit weight, and unconfined compressive strength. Analytical testing was also conducted on selected samples for Clean Construction Demolition Debris (CCDD) certification of the soil.
