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Murray Johnson, P.Eng., P.E.

Milton Madison Bridge

Main Spans (Trusses) Design and Construction

Existing Bridge

Proposed

Bridge

Bid Documents

Truss Design

Plan View – Before Sliding – Old & New Bridge

Elevation of Completed New Bridge

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Truss Design

• Permanent Bridge Design Features

• Design-Build Challenges for Steel

Truss Bridge

• Bridge Design

Adapted for Construction

Techniques

Truss Design

Truss Design

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Truss Design

Bearings

Main Spans: Construction Sequence

Float in Span 2

Lift

Span 2

Cantilever Span 1

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Main Spans: Construction Sequence

Float in & Lift Span 3

Cantilever Span 4

Slide Completed

Bridge Laterally

Main Spans: Construction Sequence

Existing Bridge

New Pier Cap

Temporary Pier

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Temporary Piers

Barge Impact

Temporary Piers –Barge Impact Protection Frames

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Barge Impact Protection Frames

Barge Impact Protection Frames

Towers

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Temporary Pier Connection to Pier

Towers

Lifting Frames

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Temporary Pier at Lifting

Stability Frames

Sliding Girders

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Sliding Girders

Sliding Girders

Sliding Girders

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Span Lifting

Preassembly of Steel Trusses on Barges

Span Lifting

Span Lifting

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Span Lifting

Span Lifting

Span Lifting

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Span Lifting

Span Lifting

Span 3 Lifting

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Sliding Girder Installation

Sliding Girder Installation

Sliding Girder Installation

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Sliding Girder Installation

Sliding Girder Installation

Sliding Girder Installation

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Sliding Girder Installation

Sliding Girder Installation

Temporary Restraints

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Side Span Cantilever Construction

Erection Bents

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Demolition

New Pier Caps

New Pier Caps

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Truss Sliding

The Numbers:

•2433 Feet Long

•4 Spans Continuous

•15,260 Tons

•Lateral Move 55 Feet

Sliding Main Spans

Truss Sliding

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Truss Sliding

Sliding Bearings

Sliding Surface

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Strand Jacks for Sliding

Pulling Frames

Pulling Frames

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Bearing Sliding Harnesses

Bearing Sliding Harnesses

Bearing Sliding Harnesses

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Slide Control

Slide Control

Slide Control

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Main Span Sliding: Time-Lapse Video

› Video is in PPT version; in PDF version, go to:

› http://www.miltonmadisonbridge.com/gallery/video/milton-madison-bridge-slide/

Slide Complete

Lessons Learned

• develop construction scheme as far as possible

(including during bid design) before committing to material order sizes

• be prepared for potential rejection of modifications

to the permanent design to accommodate construction, have a backup plan

• friction can be too low as well as too high!

• no bridge is too big for a lateral slide!

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Questions?

Thanks to the following for photos and

other material included in this presentation :

• Charlie Gannon, Walsh Construction

• Deborah Crawford

• Michael Baker International