Slope Collapse and Reconstruction
Challenges Solved
When an unsupported earth slope failed in Skokie, IL in 2015, the rails of Chicago’s Yellow Line commuter train were undermined, and an adjacent braced cofferdam collapsed. MRCE was immediately called in to investigate the cause of collapse and restore rail service. MRCE geotechnical services included CPT probes, borings, and laboratory testing of embankment and natural clays, forensic investigations and analysis of the slope, slope stabilization with sheet pile, slope reconstruction with cement stabilized slide debris spoils, and rail bed preparation. MRCE structural services included design of structural bracing connection improvements and construction stages for a second cofferdam which did not collapse, and forensic inspection of damaged structural elements from the first cofferdam on removal. MRCE track reconstruction designs were reviewed and approved by the Chicago Transit Authority; the cofferdam revisions were reviewed and approved by the Metropolitan Water Reclamation District of Greater Chicago.