HBM-CTA Red Line Station at Wilson-converted

Description of Project

The Red Line Station at Wilson Avenue consists of a new station house (main entrance) on the south side of Wilson, a new auxiliary entrance on the north side of Wilson, a new auxiliary entrance at Sunnyside, two new 520-feet long platforms, ramps, stairs, elevators, and canopy, and a new vehicle storage building foundation for a prefabricated metal building near Montrose.

The proposed improvement of the 4-track structure at Wilson, from existing Bent 7102 to 7138, includes complete removal and replacement of the superstructure (for an approximate distance of 1700-feet). The structure width varies between 60-and 130-feet. The proposed superstructure is composed of steel track stringers, steel bents, concrete deck and concrete sound walls. The review included independent analysis and design checks at four representative bents and four representative foundations. Design checks were performed on a representative sample (10%) of the structural components.

The staging was sequenced to accommodate a single track being removed from service at the time, beginning with the western-most track and continuing in sequence toward the east, across four mainline tracks. The existing and proposed bent configurations required temporary shoring (falsework towers and concrete footings). The peer review was limited to the review of the structural adequacy of the details that were shownon the design plans.

The proposed improvements at Wilson Transfer Station included construction of a new deep foundation which consists of 146 caissons (45 of which are for the new north abutment), 4 micropile supported footings, strip footings and temporary footings. The building structure drawings and loading calculations were utilized for the review of the corresponding deep foundations (caissons and micropiles).

Temporary earth retention system were required for construction of the caissons, micropiles, and grade beam foundations. All relevant structural drawings, sketches, shop drawings, specifications, geotechnical reports, and calculations that were provided, as well as all documentation required for an OUC Deep Foundation Review were in accordance with up-to-date City of Chicago requirements.

Description of Scope of Work

• Structural Review of Station House, Platform, Canopy and Related Structures.
• Structural Review of Building Rehabilitation
• Structural Review of Track Structure
• Deep Foundation Review
• Review of Temporary Earth Retention Systems