rohleder presentation

Segmental Bridge Technology –Established and Evolving

W. Jay Rohleder, Jr, P.E., S.E. Senior Vice President / Project Development

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Segmental Bridge Topics Addressed

• Definition of concrete segmental bridge construction methods and related design considerations.

• The evolution of concrete segmental bridge technology over the past 30 years in the U.S.

• Design principles and practices that provide the economic and durability value for this structure type.

• Continuing evolution of the segmental bridge construction technology and related design concepts.

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Definition of Segmental BridgesBridges, that are typically concrete box structure types, constructed using repetitive elements that are progressively connected together to form a completed structure. Construction Load Cases are particularly critical considerations in developing the design and building methods for segmental bridges.

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CABLE STAYED BRIDGESCABLE STAYED BRIDGES

LONG SPAN BRIDGESLONG SPAN BRIDGES ENVIRONMENTALLY SENSITIVEENVIRONMENTALLY SENSITIVE

LONG BRIDGES OVER WATERLONG BRIDGES OVER WATER ARCHESARCHES

URBAN BRIDGESURBAN BRIDGES

SEGMENTAL BRIDGE APPLICATIONS

RAIL BRIDGESRAIL BRIDGES

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Segmental Bridge Methods, Components and Evolution

of the Technique

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Segmental Construction Methods• SPAN-by-SPAN (Precast)

• CANTILEVER (Precast or Cast-in-Place)> Balanced> Uni-Directional

• INCREMENTAL LAUNCH(Typically an Inefficient use of materials,

so Not commonly used –need tangent or constant curvature)

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Segmental Construction Methods• Span by Span

JFK AirTrain, NY City

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• Balanced Cantilever

Sagadahoc Bridge, ME

Segmental Construction Methods

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• Uni-Directional Cantilever (shown)• Mixed Methods

Garcon Point Bridge, FL

Segmental Construction Methods

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Precast Joints

• Keys (i.e. no reinforcing across joints)• Epoxy

– Temporary Clamping– Temperature

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• Reinforcing Bars• Joint Preparation• Bulkheads

Cast-in-Place Joints

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Post-Tensioning (PT) Arrangements

Layout Orientation• Longitudinal

– Span by Span– Cantilever

• Transverse• Vertical

Placement Type• Internal Tendons• External Tendons

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• Internal Tendons– Transverse– Longitudinal

(Cantilever)

Post-Tensioning (PT) Arrangements

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Post-Tensioning

Pre-Tensioning

Internal Transverse Pre-Stressing

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• External Tendons, LongitudinalSingle Point Deviators

Post-Tensioning (PT) Arrangements

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• External Tendons, LongitudinalMulti-Point Deviators

Post-Tensioning (PT) Arrangements

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Post-Tensioning (PT) Arrangements

• Vertical Tendons(in Precast Piers)

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Construction Engineering• Camber• Geometry Control• Prestressing Parameters• Erection Loads• Erection Equipment• Casting and Erection Manuals• Integrated Shop Drawings

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Precasting Yard Operations

• Pre-Tied Reinforcing Cage Jigs• Casting Beds

> Long Line> Short Line

• Storage & Delivery

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• Long Line Segment Casting

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• Short Line Segment Casting

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TYPICAL CASTING YARD LAYOUT

Batch Plant

Segment Storage

Rebar Jigs

Casting Beds

Segments in Storage

Possible Double Stack

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JFK AirTrain, NY, NY

9 Miles of Elevated Precast Segmental Bridge

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• 5,500 Segments• 14 Casting Cells

Precasting Facility - JFK AirTrain

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Precasting Facility - JFK AirTrain

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Segment DeliveryPrecasting Facility - JFK AirTrain

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I-93 Viaducts & Ramps, Boston, MA

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Precast plant 85 miles away by truckPrecasting Facility – I-93 Viaducts, Boston

85 Mile

s

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• 15 Acres• 1250 Segments• Casting Cells

4 Typ., 1 Combined

Precast plant in Sanford, MEPrecasting Facility – I-93 Viaducts, Boston

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Central concrete delivery - casting 3 beds / dayPrecasting Facility – I-93 Viaducts, Boston

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• 1040 – Total Segments(958 Typical, 82 Specialty)

• 3 - Typical Casting Cells• 1 - Specialty Casting Cell

Precasting Facility – Susquahanna River, PA.

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Susquehanna River Bridge, PA

• Assembly Line – Reinforcing Cage Jig

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• Assembly Line – Casting Bed Set-Up

Susquehanna River Bridge, PA

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Match CastSegment

Wet CastSegment

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• Assembly Line – Segment Pour

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• Assembly Line – Steam Cured Segments

Susquehanna River Bridge, PA

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• Segment Storage Handling,Lifting with Strap under Wing

Susquehanna River Bridge, PA

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• Segment Handling

Lifting with Bars through Lifting Holes

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1

2

3

• Segment Storage

Three Point Supports

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• Segment Storage

Double Stacking

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PRECAST SUPERSTRUCTUREComparison Table

Project: Susq. I-93 JFK Victory Sagadahoc(Pa.) (Ma.) (NY) (NJ) (Maine)

No. Segments - 1040 1250 5409 927 202 Max. Wt. (Tons) - 105 80 38 82 100 No. Typical Beds - 3 4 11 8 1 Casting Yard Size - 20 A 15 A N/A N/A 12 A

Cast 1 Segment / Day / Bed

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Precast SegmentalSpan-by-Span Construction

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SECTION A-AA

A

Typical Span-by-Span Erection

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•Advance Truss to Next Span

Typical Span-by-Span Erection

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•Deliver Segments•Set Segments

Typical Span-by-Span Erection

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•Deliver Segments•Set Segments

Typical Span-by-Span Erection

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•Epoxy Joints•Join Segments

•Deliver Segments•Set Segments

Typical Span-by-Span Erection

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•Epoxy Joints•Align Pier Segm.

•Deliver Segments•Set Segments

Typical Span-by-Span Erection

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•Align Pier Segm.•Thread Tendons•Cast Closure

•Deliver Segments•Set Segments•Epoxy Joints

Typical Span-by-Span Erection

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•Stress Tendons•Lower Truss andRepeat Process

SECTION A-AA

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Typical Span-by-Span Erection

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- Underslung Trusses- Overhead Gantry- Falsework Supports

Precast Span-by-SpanSegments Erected using:

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ERECTION TRUSSES – Under Bottom Soffit

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Deck Designed for Support ConditionERECTION TRUSSES – Under Wings

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ERECTION with OVERHEAD GANTRY

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• Tower on FoundationERECTION TRUSS SUPPORTS

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• Pier BracketERECTION TRUSS SUPPORTS

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Delivery of Segments from AboveSpecialized Erection Equipment

WMATA, VA

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SPAN-BY-SPAN CONSTRUCTION EXAMPLEMay 2007

Susquehanna River Bridge, PA

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Casting Yard

Pennsylvania Turnpike

Commission

Bridge –East Approach

Susquehanna River Bridge, PA

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West EndCalverIslandEast End

Casting Yard

New WB

New EB

Existing Bridge

Twin Bridges with each:• 5,910’ Long by 57’ Wide• 40 Spans – 35 @ 150’, 5 @ 132’• 21 River Piers• 18 Land Piers

Susquehanna River Bridge, PA

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ONE

THREE

TWO

ERECTION PHASES

Susquehanna River Bridge, PA

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Casting YardCasting Yard

Segment Segment ErectionErection

Access RoadAccess Road

Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

Segments Delivered from Storage

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Segments Delivered from Above

Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

Segment Alignment

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

ELEVATION

SECTION VIEWS

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Susquehanna River Bridge, PA

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Susquehanna River Bridge, PA

Activities Off the Critical Path

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Achieved Typical Span x Span

Erection Rate of 2 Spans per Week

Susquehanna River Bridge, PA

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VERTICAL CLEARANCES

RAILROAD LINESLOCAL AIRPORT

Susquehanna River Bridge, PA

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November 2004 - NTPMay 2007 - New Bridge Complete

Susquehanna River Bridge, PA

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• Quick, Simple Erection (2 - 3 Spans / Week)• Easy Geometry Control• Savings from less MOT• Minimum User Delays• Cost Effective• Simple Design• Durable Structures

ADVANTAGES OF SPAN-BY-SPAN

Beautiful Bridges

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Precast SegmentalBalanced Cantilever Construction

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Balanced Cantilever Erection

ERECTION SEQUENCE I

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Balanced Cantilever Erection

ERECTION SEQUENCE II

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ERECTION SEQUENCE IV

ERECTION SEQUENCE III

Balanced Cantilever Erection

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- Barge-mounted cranes- Ground based cranes- Beam and Winch- Overhead Gantry

Precast Balanced Cantilever Segments Erected using:

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BALANCED CANTILEVER EXAMPLE

September 2007

Victory Bridge, NJ

• Twin 3,971’ Long Bridges• Main Span Unit 330’, 440’, 330’• 100’ Tall Precast Piers• SxS Appr., B.C. Main Span Unit

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Victory Bridge, NJ

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Victory Bridge, NJ

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Victory Bridge, NJ

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Victory Bridge, NJ

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Victory Bridge, NJ

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Victory Bridge, NJ

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Victory Bridge, NJ

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Average production:4 to 6 segments/day (45 ft)

Balanced Cantilever Erection

Victory Bridge, NJ

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Victory Bridge, NJ

1st Bridge Open to Traffic in 15 mo.2nd Bridge Completed in 9 mo.

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Cast-in-Place SegmentalBalanced Cantilever Construction

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Wabasha Street Bridge, MN

1,248’ Long Twin Bridgeswith 398’ Main Spans

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Wabasha Street Bridge, MN

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Wabasha Street Bridge, MN

Continue through the Winter

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Blending shapes, texture and color Wabasha Street Bridge, MN

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Segmental BridgesMixing Construction Erection

Methods

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Sagadahoc Bridge, ME

3,000’ Bridge with420’ Main Span

over Kennebec River

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68’ Roadway with2 Cell Box Girder

Cast-in-Place Approach Units, with Precast

Main Span Unit Sagadahoc Bridge, ME

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520,000 sf of Structures - Completed Nov. 2002

I-93 Ramps & Viaducts, Boston MA

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I-93 Ramps & Viaducts, Boston MA

Span-by-Span Construction

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I-93 Ramps & Viaducts, Boston MA

Balanced Cantilever Construction

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Mid-Bay Bridge, FL

• Span-by-Span Approaches• One-Directional Cantilever Main Span

CIP low level piers

P/C high level piers

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Precast Segmental Piers

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Precast Piers

Directionof Erection

Erect 1 Segment an Hour,Approximately 1 Pier per Day

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Victory Bridge, NJ

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First segment cast6 weeks after NTP

Precast Piers

Victory Bridge, NJ

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Precast Piers Casting Bed

Victory Bridge, NJ

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Typical Precast Pier Details

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Precast Pier Erection

Victory Bridge, NJ

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Precast Pier Erection

Victory Bridge, NJ

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Precast Pier Erection

Victory Bridge, NJ

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Precast Pier Erection

Victory Bridge, NJ

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Precast Pier Erection

Victory Bridge, NJ

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Precast Pier Erection

Victory Bridge, NJ

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First pier erected5 months after NTP

Completed Precast Piers

Victory Bridge, NJ

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Cable StayedSegmental Superstructure

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U.S. Senator William V. Roth Jr. Bridge over C&D Canal, DE

1st concrete cable-stayed bridge in the Northeast – 1995

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Entirely Precast Segmental Bridge

U.S. Senator William V. Roth Jr. Bridge over C&D Canal, DE

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Segmental Cable-Stay BridgesI-280 Veterans’ Glass City Skyway, Ohio

1,225’ main span (2 @ 612’-6”)

Penobscot Narrows Bridge& Observatory, Maine (1,161’ main span)

Open Dec. 2006

Open June 2007

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Veterans’ Glass City SkywayPrecast SuperstructureCompleted in 8 Months

New Penobscot Narrows BridgeCast-in-Place SuperstructureCompleted in 15 Months

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Penobscot Narrows Bridge & Observatory, ME

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CIP Balanced Cantilever Construction

FormTraveler

FormTraveler

Penobscot Narrows Bridge & Observatory, ME

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Penobscot Narrows Bridge & Observatory, ME

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Penobscot Narrows Bridge & Observatory, ME

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Carbon Fiber Composite Strand Demonstration Project

Penobscot Narrows Bridge & Observatory, ME

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Veteran’s Glass City Skyway, Ohio

Veteran’s Glass City Skyway, OH

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Typical Pre-Cast Cross-Sections: Main SpanVeteran’s Glass City Skyway, OH

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Main Span Precast Segmental Construction

• Backspans: Span-by Span• Mainspan: One-Directional Cantilever

Veteran’s Glass City Skyway, OH

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• 3 pairs of segmentserected in cantilever– Epoxied segment joints– Segments post-tensioned

Veteran’s Glass City Skyway, OH

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Segmental Bridge Construction Benefits• Rapid Construction• Segments Delivered over Completed Spans

– No Need for Barge Delivery• Maintained Shipping Lanes at All Times

– Access to Port of Toledo

Veteran’s Glass City Skyway, OH

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Review Questions• Define a segmental concrete bridge structure type?• List 3 methods for constructing segmental bridges? • List benefits during construction that result from

using a segmental bridge construction technique?• List permanent bridge site layout benefits resulting

from using a segmental box girder bridge type?• What structural benefits apply to using a closed cell

box girder for a segmental bridge?• What segmental bridge technological advances offer

the most immediate benefits?

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Open-ended Assignment Questions

Can you identify a viable candidate location for a segmental bridge given your understanding of the potential benefits from using this structure type?

What new innovative applications of the segmental bridge construction technique can you envision?

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America Deserves Beautiful

Bridges

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