Cook County, IL

GSG performed the subsurface exploration, laboratory testing and geotechnical analyses in accordance with all applicable standards including AREMA, ASTM and IDOT Geotechnical and SSRBC Manuals. GSG’s services included the following:  

  • Secure drilling permits from Metra/UPRR.
  • Advance 23 soil borings within the vicinity of the proposed improvements.
    • A total of 21 soil borings were drilled to a depth of up to 10 feet for the proposed track improvements
    • 2 soil borings were drilled to depths of 80 feet, including bedrock cores for the bridge improvements.
    • Collected concrete cores of the existing bridge foundations
    • Completing laboratory testing program based on the nature of subsurface soil samples collected, and inspecting rock core samples and determining rock-quality designation (RQD) and performing unconfined compressive strength test.

Geotechnical analyses included derivation of soil parameters for design, soil settlement, seismic parameters, and scour considerations. GSG provided recommendation regarding subgrade stability and treatment for the new tracks GSG also conducted geotechnical engineering analyses and evaluation of the existing foundation capacities of the existing bridge structure for the additional anticipated loads.