The diverging diamond interchange project at I-80 and Houbolt Road included 51 soil borings and rock coring for retaining walls, slope walls, ramps, water main, and roadway improvements. Laboratory testing included moisture content tests and unconfined compressive strength tests, grainsize analysis, Atterberg limits, and Illinois Bearing Ratio tests. The Structure Geotechnical Report (SGR) included foundation design recommendations for the retaining walls, slope wall earth anchors, and for the box culverts. The investigation was performed in accordance with IDOT Geotechnical Manual and the SGR was prepared in in accordance with IDOT Bridge Manual guidelines.
