Spliced Girders A Producer’s Perspective

Spliced GirdersSpliced GirdersA Producer’s PerspectiveA Producer’s Perspective

byby

Chad SaundersChad SaundersChief EngineerChief Engineer

Bayshore Concrete ProductsBayshore Concrete Products

presented at thepresented at the

Virginia Concrete ConferenceVirginia Concrete ConferenceRichmond, VirginiaRichmond, Virginia

March 11, 2005March 11, 2005

Bayshore Concrete ProductsBayshore Concrete ProductsCape Charles, VACape Charles, VA

90 acre casting facility on Cape Charles Harbor and Chesapeake Bay

The shape. How did we get The shape. How did we get here?here?

PCEFPCEFPrestressed Concrete CommitteePrestressed Concrete Committee

for Economic Fabricationfor Economic Fabrication

A committee established by FHWA for economic fabrication A committee established by FHWA for economic fabrication of prestressed/precast concreteof prestressed/precast concrete

Consists of Mid Atlantic statesConsists of Mid Atlantic states

PCEF Cross Section VariabilityPCEF Cross Section Variability

6”6” 7” 7” 8” 8”

Different web thicknesses = diff. soffitDifferent web thicknesses = diff. soffit

PCEF Cross Section VariabilityPCEF Cross Section Variability

58”58” 59” 59” 60” 60”

12” wider top flange = same side form12” wider top flange = same side form

with blockout removedwith blockout removed

Form modificationForm modification

VDOT PCBTVDOT PCBT 32” bottom flange width32” bottom flange width 7” thick bottom flange7” thick bottom flange 7” web7” web 47” top flange width47” top flange width

DESIGNATION DEPTH AREACENTROID

TO BOTTOMMOMENT

OF INERTIAWEIGHT

(150 PCF)

  (IN) (IN2) (IN) X 103 (IN4) LBS/LF

PCBT-29 29 634.7 14.66 66.8 661

PCBT-37 37 690.7 18.43 126.0 720

PCBT-45 45 746.7 22.23 207.3 778

PCBT-53 53 802.7 26.06 312.4 836

PCBT-61 61 858.7 29.92 443.1 899

PCBT-69 69 914.7 33.79 601.3 953

PCBT-77 77 970.7 37.67 788.7 1011

PCBT-85 85 1026.7 41.57 1007.2 1070

PCBT-93 93 1082.7 45.48 1258.5 1128

Rte 123 over the Occoquan Rte 123 over the Occoquan RiverRiver

Fairfax and Prince William CountiesFairfax and Prince William Counties

VDOT’s first PCBT VDOT’s first PCBT spliced girder spliced girder

bridgebridge

LocationLocation

Close proximity to I-95 and Route 1 = detour = high trafficClose proximity to I-95 and Route 1 = detour = high traffic

Town of OccoquanTown of Occoquan

Affluent neighborhood = pressure for aesthetic Affluent neighborhood = pressure for aesthetic designdesign

Who’s WhoWho’s Who

Owner – VDOTOwner – VDOT Designer – Moffatt & NicholDesigner – Moffatt & Nichol General Contractor – Archer WesternGeneral Contractor – Archer Western Erection Engineer – McNary BergeronErection Engineer – McNary Bergeron Precast – Bayshore Concrete Precast – Bayshore Concrete

ProductsProducts PT Hardware - VSLPT Hardware - VSL

Erection planErection plan

End Span Haunch Drop In Haunch End SpanEnd Span Haunch Drop In Haunch End Span

Approach Girders (4 spans)Approach Girders (4 spans)

Bridge Cross SectionBridge Cross Section

At Haunch At Haunch PiersPiers

Other piersOther piers

ConcreteConcrete

Concrete – 28 day: 8000 psiConcrete – 28 day: 8000 psi Concrete - release: 5800 psiConcrete - release: 5800 psi Low permeabilityLow permeability Release strength cylinders matched Release strength cylinders matched

curedcured

ApproachApproach

GirdersGirders 4 span unit4 span unit Pieces: 58 total beamsPieces: 58 total beams Type: PCBT-77Type: PCBT-77 Length: 144 ftLength: 144 ft Weight: 73 tonsWeight: 73 tons Strand: 0.6” LRSStrand: 0.6” LRS Cast two per pourCast two per pour

Cross sectionCross section

Approach Girder Casting setupApproach Girder Casting setup

Conventionally prestressedConventionally prestressed

with draped strandswith draped strands

Gravity abutment to Gravity abutment to withstand prestress withstand prestress forceforce

Maturity meter testingMaturity meter testing

Research for Research for more accurate more accurate prediction and prediction and control of control of camber by VA camber by VA TechTech

Forms and castingForms and casting

Placing concrete with Placing concrete with TuckerbuiltTuckerbuilt

Side forms with fall Side forms with fall protection railprotection rail

StorageStorage

300 ton twin gantry crane in background300 ton twin gantry crane in background

Spliced GirdersSpliced GirdersEnd spanEnd span Pieces: 28 total beamsPieces: 28 total beams Length: 127 ftLength: 127 ft Weight: 88 tonsWeight: 88 tons

HaunchHaunch Pieces: 28 total beamsPieces: 28 total beams Length: 98.5 ftLength: 98.5 ft Weight: 77 tonsWeight: 77 tons

Drop-InDrop-In Pieces: 14 total beamsPieces: 14 total beams Length: 137 ftLength: 137 ft Weight: 87 tonsWeight: 87 tons

Special form needsSpecial form needsEnd span and Drop-InEnd span and Drop-In 34” soffit34” soffit (4) sections of end block form (end span only)(4) sections of end block form (end span only) Extra 2” angle full length of side forms to create 6” thick Extra 2” angle full length of side forms to create 6” thick

top flangetop flange

HaunchHaunch Complete form system including soffit and side formsComplete form system including soffit and side forms

ApproachApproach Standard PCBT-77Standard PCBT-77

Erection SequenceErection Sequence

TemporaryTemporary

supportsupport

Erect haunch Erect haunch segment then end segment then end span segmentspan segment

Back span = 185 Back span = 185 ftft

Erect drop-in Erect drop-in segmentsegment

Main span = 225 Main span = 225 ftft

Erection SequenceErection SequenceMake closures Make closures and begin PTand begin PT

Remove strong Remove strong backsbacks

Cast deck and Cast deck and complete PTcomplete PT

End Span and Drop InEnd Span and Drop Incross sectionscross sections

End Span and Drop-In End Block at End End Span and Drop-In End Block at End SpanSpan

Type: Modified Type: Modified PCBT-77PCBT-77

Depth: 79” Depth: 79”

Strand: 0.6” LRSStrand: 0.6” LRS

Variations:Variations:

6” thick top 6” thick top flangeflange

9” wide web for 9” wide web for PT tendons = PT tendons = 34” wide bottom 34” wide bottom flange & 49” flange & 49” wide top flangewide top flange

Cast two per Cast two per pourpour

End Span End Span end conditionend condition

PT ducts: (3) 4” OD for 0.6” LRSPT ducts: (3) 4” OD for 0.6” LRS

Extremely congested area due to bursting reinforcementExtremely congested area due to bursting reinforcement

End Span and Drop-In End Span and Drop-In connectionconnection

at splice with haunch at splice with haunch

Very congested area due to splice plates with welded rebar and Very congested area due to splice plates with welded rebar and projecting rebarprojecting rebar

Casting setupCasting setup

Setting ductsSetting ducts

Ducts in placeDucts in place

End blockEnd block

Up close near Up close near anchorageanchorage

Horizontal Horizontal reinforcementreinforcement

End blockEnd block

Pre-assembly of end Pre-assembly of end cagescages

Termination of end Termination of end blockblock

Splice EndSplice End

Top splice Top splice platesplates

Bottom plates and projecting Bottom plates and projecting barsbars

HaunchHaunchType: Modified Type: Modified PCBT-77PCBT-77

Depth: varies Depth: varies from 79” to 12’-from 79” to 12’-6”6” Strand: 0.6” LRSStrand: 0.6” LRS

Variations:Variations:6” thick top 6” thick top flangeflange9” wide web for 9” wide web for PT tendons = PT tendons = 34” wide bottom 34” wide bottom flange & 49” flange & 49” wide top flangewide top flange

Cast one per Cast one per pourpour

HaunchHaunch

ChallengesChallenges:: 12’-6” depth at midpoint = extreme height full length12’-6” depth at midpoint = extreme height full length Most strands located in top flangeMost strands located in top flange Location of the PT tendons makes concrete placement and Location of the PT tendons makes concrete placement and

consolidation difficult = addition of pour windows consolidation difficult = addition of pour windows Extra setup required for storing and handling of variable Extra setup required for storing and handling of variable

depth side forms and beamsdepth side forms and beams

NTS

nts

Bed setupBed setup

Pulling strandPulling strand

StressingStressing

Rebar andRebar andPT tendonsPT tendons

How did he tie the bars How did he tie the bars in the top flange?in the top flange?

FormsForms

Top Splice PlateTop Splice Plate

Grout ventsGrout vents

Pouring with Pouring with bucketsbuckets

Look at the view Look at the view from up here.from up here.

Girder bracingGirder bracing

First casting is a First casting is a successsuccess

ShippingShipping

All beams to be shipped by barge All beams to be shipped by barge starting early April 2005starting early April 2005

ErectionErection

Phase I – setting Phase I – setting beams from the beams from the existing bridgeexisting bridge

ErectionErection

Phase II – setting Phase II – setting beams from the beams from the phase I bridgephase I bridge

Lessons learnedLessons learned Producer - Seek possible use of SCC concrete for Producer - Seek possible use of SCC concrete for

heavily congested areaheavily congested area Contractor - Get “construction engineer” involved Contractor - Get “construction engineer” involved

early to ensure means and methods are early to ensure means and methods are established (i.e. temporary bracing embedments, established (i.e. temporary bracing embedments, special lifting requirements, strong back design, special lifting requirements, strong back design, etc.)etc.)

Engineer - Require complete shop drawings from Engineer - Require complete shop drawings from PT supplierPT supplier

DOT – consider having a notch in back span DOT – consider having a notch in back span girder(s) designed and included in plans to ensure girder(s) designed and included in plans to ensure maximum flexibility in construction sequencemaximum flexibility in construction sequence

Rte 33 over the Pamunkey Rte 33 over the Pamunkey RiverRiver

West Point and New Kent CountyWest Point and New Kent County

What’s Next?What’s Next?

LocationLocation

Town of West PointTown of West Point

Who’s WhoWho’s Who

Owner – VDOTOwner – VDOT Designer – Parsons BrinckerhoffDesigner – Parsons Brinckerhoff General Contractor – Tidewater General Contractor – Tidewater

SkanskaSkanska Precast – Bayshore Concrete Precast – Bayshore Concrete

ProductsProducts

ConcreteConcrete

Concrete – 28 day: 8000 psiConcrete – 28 day: 8000 psi Concrete - release: 6000 psiConcrete - release: 6000 psi Low permeabilityLow permeability Lightweight: 115 pcf (concrete)Lightweight: 115 pcf (concrete)

125 pcf (total)125 pcf (total)

ApproachApproach

GirdersGirders3 span unit3 span unitPieces: 21 total beamsPieces: 21 total beamsType: Modified PCBT-93Type: Modified PCBT-93

Variations:Variations:9” thick bottom flange9” thick bottom flange8” wide web = 33” wide bottom 8” wide web = 33” wide bottom

flange & 60” wide top flangeflange & 60” wide top flange

Depth = 95.5”Depth = 95.5”Length: 137 ftLength: 137 ftStrand: 0.5” LRSStrand: 0.5” LRSCast two per pourCast two per pour

Cross sectionCross section

Spliced GirdersSpliced Girders

End spanEnd span Pieces: 42 total beamsPieces: 42 total beams Length: 159 ftLength: 159 ft

HaunchHaunch Pieces: 28 total beamsPieces: 28 total beams Length: 80 ftLength: 80 ft

Drop-InDrop-In Pieces: 28 total beamsPieces: 28 total beams Length: 159 ftLength: 159 ft

HaunchHaunchType: Modified Type: Modified PCBT-93PCBT-93

Depth: varies Depth: varies from 95.5” to from 95.5” to 10’-5 1/2”10’-5 1/2” Strand: 0.6” LRSStrand: 0.6” LRS

Variations:Variations:8” wide web for 8” wide web for PT tendons = PT tendons = 33” wide bottom 33” wide bottom flange & 60” flange & 60” wide top flangewide top flange

Cast one per Cast one per pourpour

HaunchHaunch

Challenges:Challenges: 10’-5 ½” depth at midpoint = setup remains at 12’-6” to 10’-5 ½” depth at midpoint = setup remains at 12’-6” to

avoid costly rework = extreme height full lengthavoid costly rework = extreme height full length Others same as previous project.Others same as previous project.

Pros:Pros: Not having to set up a new stressing frameNot having to set up a new stressing frame Booster Form – utilize existing formsBooster Form – utilize existing forms

Special form needsSpecial form needsEnd span and Drop-InEnd span and Drop-In 33” soffit33” soffit (2) sections of end block form (end span only) – different (2) sections of end block form (end span only) – different

from Occoquan because same quantity of end span and from Occoquan because same quantity of end span and drop-indrop-in

16” riser for PCBT-77 form16” riser for PCBT-77 form

HaunchHaunch Booster form (bolts on to bottom of standard form)Booster form (bolts on to bottom of standard form)

ApproachApproach 16” riser for PCBT-77 form (same as above)16” riser for PCBT-77 form (same as above)

Questions?Questions?

Thank YouThank YouPlease feel free to come visit Please feel free to come visit

our plant OR call if we can our plant OR call if we can be of assistance in any waybe of assistance in any way

Contact: Joe RoseContact: Joe Rose757-331-2300 jrose@bcpcorp.com757-331-2300 jrose@bcpcorp.com

Bayshore Concrete ProductsBayshore Concrete ProductsCape Charles, VACape Charles, VA

90 acre casting facility on Cape Charles Harbor and Chesapeake Bay