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Life-Cycle Engineering Services | EXPANDED

Modjeski and Masters is pleased to announce the acquisition of structural engineering firm Summit Engineering Group, Inc. Our combined engineering prowess and respective technical skillsets will enable us to provide streamlined design and construction solutions to best meet client needs.

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Government Swing Bridge Rehabilitation

| View Projects:USA Rock Island Arsenal, IL

  • Client:

    U.S. Army Rock Island Arsenal Department of Public Works
  • Service:

    Movable Bridges
  • Status:

    Completed
  • Overview

    Still going strong – this phrase best describes the current Government Bridge crossing. Completed in 1896, and fully operational today, the double-deck highway/railroad swing bridge was the first bridge designed by M&M founder Ralph Modjeski. The current crossing is the fourth bridge installment at Rock Island Arsenal – replacing three others that were constructed beginning in the early 1850s. In recent years, the useful fatigue life of the Government Bridge was considered exhausted and the bridge was scheduled for replacement by the stakeholders. However, our problem solvers believed that a more sustainable alternative to replacing the historic swing bridge could be found.

    Working with the U.S. Army Rock Island Arsenal Department of Public Works, Modjeski and Masters’ technical experts performed a new fatigue study which included a comprehensive review of historical train loading on the bridge. We also installed strain gages on fracture-critical members to compare actual stress ranges with theoretical values. Our analysis showed that the bridge had only utilized a small portion of its useful fatigue life, confirming our belief that the bridge could be cost-effectively rehabilitated. Next, our knowledgeable structural, electrical, and mechanical engineers utilized the latest Illinois DOT Standard Specifications, in conjunction with the AREMA Manual, for the rehabilitation design of construction repairs. As active partners, M&M led a series of rehabilitation assignments to maintain this long-standing connection. We completed analysis of strain gauge data for the fatigue study, performed a load rating of the truss and highway/rail floorsystems, and provided services to improve vertical clearance of the end portals. Collectively, our experienced engineers designed various structural, mechanical and electrical details for the successful rehabilitation of the bridge, including upgrades to and replacement of the bridge’s movable machinery and drive system.

    Over the past several years, Modjeski and Masters has been privileged to provide lifecycle bridge engineering services to ensure that the Government Bridge remains reliable for many years to come. Of any project in our proven portfolio of bridge work, perhaps none is as exemplary of our commitment beyond completion. Our long-term relationship with the U.S. Army Rock Island Arsenal was established over 115 years ago. And today, we continue to help them grow value through their bridge’s continued operation and service. It’s part of our promise to help build and maintain great bridges.
  • Description

    Tasks Performed
    • In-depth Structural/Electrical/Mechanical Inspection
    • Railroad Services
    • Structural/Electrical/Mechanical Rehabilitation
    • Construction Support & Inspection
    • Fatigue/Fracture Studies
    • Load Capacity Rating
    • Strain Gauge Evaluation

    Bridge Geometry
    • Main Span – 365-ft.
    • Total Length – 1,850-ft.
    • Lanes on Structure – Two lanes, two railroad tracks
  • Testimonial

    Completed in 1896, and fully operational today, the double-deck highway/railroad swing bridge was the first bridge designed by M&M founder Ralph Modjeski. As active partners, M&M led a series of rehabilitation assignments to maintain this long-standing connection.
  • Credits

    Leon K. Huang, PE (Principal-In-Charge)
    Dave W. Petermeier, PE, SE (Project Mgr. | Structural Lead)
    Lance V. Borden, PE (Electrical Lead)
    Jeffrey W. Newman, PE (Mechanical Lead)

    Photograph #2 by Daniel McDermott