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 [email protected] [email protected]
Bayshore Concrete ProductsBayshore Concrete ProductsCape Charles, VACape Charles, VA
90 acre casting facility on Cape Charles Harbor and Chesapeake Bay