Project Owner

F.H. Paschen, S.N. Nielsen

Client

Omega III, LLC

Services Provided

Structural Engineering
Demolition Analysis and Procedure

Location

Chicago, IL

Year of Demoltion

2020

43rd Street Bridge Demolition Procedure

 

HBM Engineering Group, in collaboration with Omega III, undertakes the demolition plan for the 43rd Street Pedestrian Bridge over Metra/ICRR Railroads and South Lake Shore Drive in Chicago, IL. This venture, commissioned by FH Paschen, aims to efficiently deconstruct the existing structure to facilitate the reconstruction process.

Bridge Information: The bridge comprises two types: Bridge #1, a three-span continuous steel truss over the railroads, and Bridge #2, a two-span continuous two-girder steel bridge over Lake Shore Drive. Each bridge involves meticulous span-by-span removal, including complete deck, truss members, bracing, girders, stairs, and pier/bent removal within the specified limits.

 

HBM’s Scope:

  • Structural Engineering
  • Demolition Analysis and Procedure

Demolition Procedure:

  1. The comprehensive demolition is scheduled over three nights with full track and road closures as appropriate.
  2. Safety measures include utility assessments, removal of attached elements, de-energizing catenary power lines, and strict adherence to wind speed limitations.
  3. A dedicated ground team ensures safety and demarcates danger zones, while debris removal is executed responsibly at legal recycling facilities.
  4. Steel components are treated as potentially lead-painted, with decontamination units and safety protocols in place.

Sequence of Removal:

  1. The meticulous span-wise removal proceeds from west to east, ensuring a systematic and controlled process.
  2. The removal of Bridge #1 spans (Spans 1, 2, and 3) involves crane setups at specific locations, careful cutting, and lifting with precise coordination between railroad authorities and contractors.
  3. Bridge #2 spans (Spans 4 and 5) are removed with a similar method, including saw-cutting, girder-end torch cutting, and crane lifting.
  4. The removal sequence is strategically planned for three consecutive night shifts, ensuring efficient progress.

Pier/Bent Removal:

  1. Pier and bent removal is scheduled concurrently with the respective span removal, either with excavators or crane picks.
  2. Detailed procedures involve wrecking abutments, salvaging limestone, and processing concrete for recycling.

Equipment:

  1. LR 1400 Crane
  2. 118K Excavator – CAT 349, 345, or equivalent
  3. 87k Excavator – CAT 336, 330, or equivalent
  4. 40 K loader

Structural Analysis: SAP2000 software is utilized for rigorous structural analysis, ensuring the integrity and stability of the bridge during each removal stage. The results affirm the adequacy of the bridge and crane capacities.

The project demonstrates a meticulous approach to demolition, ensuring safety, efficiency, and adherence to structural integrity. The structural analysis affirms the project's feasibility, providing a solid foundation for the successful execution of the 43rd Street Bridge demolition.