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UTAHDepartment of Transportation

ACCELERATED BRIDGE CONSTRUCTION BY 2010

How have we done?

ACCELERATED BRIDGE CONSTRUCTION BY 2010

How have we done?Fred DoehringFred Doehring

UDOT StructuresUDOT Structures

ABC by 2010

• UDOT goals– Accelerated Bridge Construction

• Standard practice by 2010

• What was needed?– Methods of construction– Standard details– Commitment to a program

Vision for “Family” of ABC Methods

Precast Concrete ElementsPrefabricatedPrefabricatedComponentsComponents

Modular Construction

Large Prefab. Large Prefab. ComponentsComponents

Structure PlacementMethods

SPMTSPMTSlidingSliding

Accelerated Bridge

Construction

Accelerated Geotech

WorkGeofoamGeofoam

Fast Track Contracting

CMGCCMGCDesign/BuildDesign/Build

ABC Phase 1

• Early implementation of ABC– Scanning Tours

• Looked at what other states were doing– Workshops held

• Brought all stakeholders together• Identified what was needed• Prioritized needs• Looked at several specific pilot projects

ABC Phase 1

• Results of Phase 1 work– Several key standards were

developed• Precast Full Depth Deck Panels• Manual on Self Propelled Modular

Transporters (SPMT’s)• Development of specifications

and manuals for each• Several pilot projects initiated and

built

ABC Methods Used

• Precast Deck Panels• Voided Slabs• Precast Substructures

– Abutments and Bent Caps• Precast Superstructures

– Crane, Sliding, and SPMT

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Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth

Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth

Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth

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Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth

Voided Slabs Voided Slabs

Precast Substructure Precast Substructure

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Precast Substructure Precast Substructure

Precast Superstructure - Crane Precast Superstructure - Crane

Precast Superstructure - Sliding Precast Superstructure - Sliding

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Precast Superstructure - SPMT Precast Superstructure - SPMT

Precast Superstructure - SPMT Precast Superstructure - SPMT

Precast Superstructure - SPMT Precast Superstructure - SPMT

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Precast Superstructure - SPMT Precast Superstructure - SPMT

UTAHDepartment of Transportation

ACCELERATED BRIDGE CONSTRUCTION BY 2010

Where are we going?

ACCELERATED BRIDGE CONSTRUCTION BY 2010

Where are we going?

Michael CulmoMichael CulmoCME Associates, Inc.CME Associates, Inc.

ABC Phase 2• Standardized the remainder of prefabricated

element types• Developed details for:

– Precast substructures• Piers, Abutments, walls, culverts

– Precast Approach slabs– Precast Girders

• Pre-tensioned Bulb Tees• Post-Tensioned Bulb Tees• Deck Bulb Tees

• Developed Specifications and Manuals• Workshops were held for industry input

ABC Phase 2

• Other work completed in Phase 2– Reviewed computer monitoring data from first

round of SPMT bridge moves– Refined Phase 1 work based on lessons

learned in construction• Deck Panel standards and specifications• SPMT Manuals

• Emulates a reinforcing steel lap splice• Used in precast parking garages and

stadiums and bridges• New seismic research coming

Connections with Grouted Splice Couplers

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Connections with Grouted Splice Couplers

Installation video on Youtube

Search “Georgia Bridge Pier” Column or wall panelto footing connection

Typical Connection Details

Column to capconnection

Typical Connection Details Current Typical Details• Single column hammerhead• Two column bent• Three column bent

Columns• Rectangular are possible,

but not preferred• Round columns are difficult

to precast– Must be cast vertically

• Use Hexagonal or octagonal shape– Can be cast on side (one side open)

Current Typical DetailsFootings• Full Precast

– For smaller footings

Shim and grout under footing through ports in footing

Current Typical Details

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Footings• Partial Precast

– For larger footings– Precast designed to support

DL of bridge– CIP extensions designed for

other loads

CIP Extension

Precast Portion

Shim and grout under footing through ports in footing

Current Typical DetailsPile supported footings

• Use corrugated pipe forms

•Used for integral abutment stems also

Current Typical Details

Pretensioned Bulb Tee Girders Pretensioned Deck Bulb Tee Girders

Post-tensioned Bulb Tee Girders Integral Abutment Details

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Cantilever Abutments and Walls• Use corrugated pipes in stems to reduce weight

– To be filled with concrete in the field– Reduces the number of pieces

1. Drive Piles

Stage 1

1. Place footings over pile and set to grade and alignment (day 1)

2. Cast concrete in voids around piles (day 1)

3. Cast concrete between footings if required (day 2)

Stage 2

1. Install pier wall panels. (day 4)2. Connect to footing via grouted

splice couplers (day 4)3. Fill voids with concrete to within

3 feet of top (day 5)4. Install rebar cage in top of voids

extending 2 feet above (day 5)5. Joints between may be grouted

or left dry

Stage 3

1. Install pier cap, set to grade (day 6)

2. Pour concrete through ports to fill voids and make connection (day 7)

3. Install precast beam seats (day 7)

Stage 4 Final Construction

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Box Culverts• Precast boxes, aprons, and walls

Tolerances

• Tolerance details developed for all critical elements

• Based on PCI Tolerance manual– MNL-135-00

Tolerance DetailsSplice couplers

Tolerance DetailsColumns

Precast Full Depth Deck Panels

• First Generation Standards completed in Phase 1 UDOT ABC Program

• More than 15 project built to date• Costs are coming down• Welded plate details are not desirable

– Time– Leakage issues at joints

• There is new technology in the market

Precast Full Depth Deck Panels• Phase 2 Modifications

– Use Longitudinal Post-Tensioning to Connect Panels• AASHTO Code Recommendation• Better performance over time (no leakage through joints)

– Use multi-strand PT systems• Developed for slabs• More Flexible

– Allow blind pockets for shear stud connection• Based on recent research

– Allow skewed deck panels (up to 15 degrees)

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Precast Full Depth Deck Panels• Recommended Post-tensioning System

– Multi-strand deck PT systems– Developed specifically for decks (thin anchorage)– Used by other states– Recommend the use of less than maximum amount

of PT allowed in the ducts (4-0.5” strand)

Blind Pocket Project – Texas DOT

UDOT Blind Pocket Details

Schematic Construction Details2 Span Bridge using UDOT Standards

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Typical 2 Span Bridge

Excavate and Install Piles

Typical 2 Span Bridge

Install Abutment Stem and Footings

Typical 2 Span Bridge

Install Pier ColumnsFill Voids in Abutment Stems

Typical 2 Span Bridge

Install Pier Cap and WingwallsCast Footing Closure Pour

Typical 2 Span Bridge

Erect Girders

Typical 2 Span Bridge

Install Backwalls and Sleeper Slabs

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Typical 2 Span Bridge

Install Deck Panels and Approach Slabs

Typical 2 Span Bridge

Cast Deck and Approach Slab Closure Pours

Typical 2 Span Bridge

Construction Roadway Approaches Bridge Monitoring (TAC)

• Volunteer group of key stakeholders– UDOT– Design Consultants– Contractors– Industry Representatives

• Charged with review of data and recommendations for future SPMT bridge moves

• Used computer monitoring data from 2008

• Data retrieved– Mostly strain data (deck, girders)– Layouts were similar on each bridge– Used to study the stresses within the bridge during:

• Lifting• Moving• Placement

• Utah State University (USU)– Brought in to analyze and disseminate the data– With input from the TAC

Bridge Monitoring (TAC)

Lifting Strain

Dynamic Strain

Temperature Strain

Typical Data

Bridge Monitoring (TAC)

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• Final Findings and Recommendations– Lifting stresses are very significant

• Supporting the deck at the lift points eliminated most deck cracking• Lift bridge closer to ends (0.2L or less)• Lightweight concrete in the deck helps to reduce deck cracking, and

overall lift weight– Dynamic effects can be approximated by increasing dead load

by 15%• Starting and stopping of SPMT’s• Traversing bumps during the move

– 3d Analysis is needed to estimate lifting stresses if a flexiblecarrying beam is used

– Recommended future gaging locations

Bridge Monitoring (TAC) SPMT Manual Revisions• Build on knowledge gained in 2008• No major changes• Define roles of project participants• Written to fit in with the UDOT Design

Network

SPMT Lifting Methods

• Neg. DL moment on girder• May be a problem with prestressed girders

• Light weight concrete could help

• Little or no deck cracking• Deck is pre-compressed in final condition

• Neg. DL moment on composite section

• Significant deck cracking is possible

• Light weight concrete could help

Lessons Learned• Study of Performance of ABC Bridges• Bridge Types Studied

– Full Depth Deck Panels with welded tie connections (6)

– Full Depth Deck Panels with Post-Tensioning (2)– Precast Parapets integral with deck (5)– SPMT Bridge Moves (9)– Precast Abutments (2)– Precast Piers (2)

• Inspections took place in May, 2009

Lessons LearnedProject locationsMilepost 200 on Route 6 not shown

Lessons Learned• Purpose of the study

– Investigate the performance of each component type

– What is performing well and what is not– Not intended to critique past designs

• Most of these bridges were designed prior to development of standards

• Many were designed as short term fixes prior to full replacement in the near future (10-25 years)

– Goal: Continuous Improvement of Quality

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Lessons Learned• Welded Tie Connections

– Joint Leakage is widespread– Shear transfer is still working– Composite connection is good

Lessons Learned• Welded Tie Connections

Lessons Learned• Welded Tie

Connections

Lessons Learned• Welded Tie Connections

Lessons Learned• Post Tensioned Connections

– 3 span continuous bridge

I-215 at 3900 South

Lessons Learned• Post Tensioned

Connections– No Joint Leakage– Even in negative

moment areas

Underside of deck

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Other Long Term Performance Information

• I-84/Route 8 Interchange –Waterbury, CT

Project Information• Curved structure (straight beams)• 6 Span bridge with continuous spans • Single lane• Prestressed transversely and post tensioned

longitudinally• Details similar to UDOT• 42 Day construction

• No construction problems• Built in 1991

After 18 years of service• Excellent condition• Used membrane waterproofing and Asphalt Wearing

surface• No leakage through joints

After 18 years of service

Route 8 Viaduct, Seymour, CT• 2 Curved structures• Over 50 spans (all simple spans)• Prestressed and post tensioned• Weekend closures only

• Old deck removed on Friday night• New deck erected on Saturday

morning• Post tensioned on Saturday night• Grouting on Sunday morning• Open to traffic Sunday night

• Asphalt wearing surface withwaterproofing membrane

• In service for 15 years• Excellent condition

Another long term example project Lessons Learned• Precast parapets integral with precast

decks– Most are good– Problem with panels cast with 2 parapets

• No transverse adjustment during installation

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Lessons Learned Lessons Learned• Precast Abutments

– Few have been built• Horizontal joints (Lego bridges)• None built to new standards yet• There were significant fit-up

problems on one bridge– Can be resolved with

appropriate casting tolerances• Performing well

Lessons Learned Lessons Learned• Precast Piers

– Few have been built• None built to new standards yet

– One is similar• Construction went well• Performing well

Lessons Learned Lessons Learned• SPMT Bridge Moves

– Deck cracking is common– Exceptions:

• Bridges cast while supported at lift points• Lightweight Concrete Deck

– Some leakage through cracks– Performing well

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Lessons Learned Lessons Learned

Lessons Learned• Cast-in-place closure pours

– Some have significant shrinkage cracks• Restraint of adjacent panels• Some leakage through cracks

Lessons Learned

Lessons Learned Lessons Learned• Shear Connector Pockets

– Several have minor leakage around pockets (not all)

• Shrinkage of Grout• Blind pockets should alleviate this

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Lessons Learned Lessons Learned• Recommendations

– Full Depth Deck Panels• Eliminate welded tie detail • Always use post-tensioning• Use blind pocket detail for shear connectors• New Standards address these recommendations

Lessons Learned• Recommendations

– Precast integral parapets• Do not use 2 per panel

– Use a longitudinal closure pour in deck to allow for adjustment in the field

– Cast one or both in the field behind temp. barriers

Lessons Learned• Recommendations

– Precast Abutments and Piers• Use vertical joints in abutment stems and wall

stems– Allows for easier fit-up in the field

• No problems noted with pier construction• New Standards address these recommendations

Lessons Learned• SPMT Moves

– TAC Committee work verifies issues found in the field

• Pick bridges closer to ends• If possible, support girders at lift points during

deck casting• Investigate the use of lightweight concrete to

reduce deck and girder stresses• New SPMT Manual will address these

recommendations

Lessons Learned• Other general recommendations

– Overlays• Consider thicker overlay with a quality

waterproofing membrane– European and East Coast Systems – CME recommendation, not UDOT policy

– Closure Pours• Use a better high early strength concrete mix

– Shrinkage compensating mixes– NY State mix is being investigated

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Where are we going?

• UDOT Themes– Accelerate Delivery

• Design and Construction– Decrease MOT

• Reduce User Costs and impact to society– Encourage Innovation– Get a good price

Where are we going?

• Implementation of Phase 2 Standards– Training

• Designers• Construction Inspectors• Bridge Inspectors• Bridge Maintenance Personnel

– On-call technical support

Where are we going?

• Manuals– Develop a Bridge Design Manual– New SPMT design guide to be issued

• Lightweight Concrete– SPMT Decks (minimize deck cracking)– Substructure Elements (reduce shipping and

handling costs)

Where are we going?

• Continue to monitor progress– Annual inspection of ABC Bridges– Address issues as they arise

• Goal: Continuous Improvement

Questions?This presentation will be posted on the UDOT website

Testing data

Grouted Splice coupler @ end of column

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Testing data

Control Column w/o Grouted Splice Coupler