• Redundancy • Overload Capacity • Insensitive to Fatigue • Fire Resistance • Deflection Control • Durability
ADVANTAGES OF CONCRETE SEGMENTAL
BRIDGES
Introduction
McNary Bergeron
Presenter
Presentation Notes
Redundancy: There are multiple external tendons inside the box. Top slab contains multiple transverse tendons and for cantilever construction, many longitudinal tendons. Overload Capacity: For many segmental structures, the construction loads are the heaviest. Insensitive to Fatigue: This type of structure is deadload predominate. Fire Resistance: Main load carrying tendons are inside the concrete box. Durability: High quality concrete is used. Also, 2 way post-tensioning provides a crack free structure.
Precast Balanced Cantilever Construction
Four Bears Bridge Ft. Berthold Indian Reservation,
North Dakota
Opened September 2005 4,500’ Bridge
FIGG
Presenter
Presentation Notes
Typical span length = 318’ Bridge utilizes an integral wearing surface. The top slab is cast with extra clear cover and then grinding is used to produce ride quality. If the deck becomes contaminated with chlorides from the environment or from use of deicing chemicals, the extra cover can be removed and an overlay applied. Why precast? The construction is seasonal due to extreme winter conditions, however casting can occur year round in enclosed work areas. Erection was performed during summer months.
Superstructure Precasting
482 superstructure segments
Casting yard near one end of the bridge
Indoor casting facility
FIGG
Casting Operations Prefabricated reinforcing cage placed in segment form
FIGG
Presenter
Presentation Notes
Prefabrication of the reinforcing steel cage expedites the casting operation. Epoxy coated reinforcement was used to increase durability.
Casting Operations Concrete placement using overhead crane and bucket
FIGG
Presenter
Presentation Notes
Left photo: The “wet cast” segment is on the left and is prepared and ready for concrete placement. The “match cast” segment is on the right. The geometry of the bridge is controlled by adjusting the alignment of the match cast segment. A bond breaker is used on the face of the match cast segment to facilitate separation of the segments. Right photo: Concrete placement of the wet cast segment. Segment fabrication was performed inside a building and allowed casting year round and during inclement weather, resulting in the production of high quality product.
Casting Operations Segment move to storage FIGG
Presenter
Presentation Notes
Cast segments are moved to a finishing station and the transported to storage. Segments are stored using 3 point supports to reduce warping and distortion.
Segment Transport FIGG
Presenter
Presentation Notes
Segments are loaded in the storage area and transported to a barge for erection. Because of the limited seasonal window for site work, total precast construction was utilized – note the precast footing shells in the right photo.
Segment Delivery FIGG
Presenter
Presentation Notes
Left photo: Loading segments on barge. Right photo: Barging segments to erection location.
Pier Table Erection FIGG
Presenter
Presentation Notes
Erection of pier table using cranes. Segments are sized based on equipment capacity. Temporary shoring is used to reduce loads into the column.
Typical Segment Erection FIGG
Presenter
Presentation Notes
Cantilever segment is lifted into position by beam and winch. The segment faces are coated with epoxy and then pulled together using temporary post-tensioning. Cantilever tendons are then installed and stressed. This process is repeated until the full cantilevers are completed.
Typical Closure Joint FIGG
Presenter
Presentation Notes
The closure is completed by aligning the cantilever ends, installing forms, reinforcing steel, and concrete. Continuity post-tensioning is then installed and stressed.
Construction Rate
Typica l Erec tion of 4 to 6 s egments per day
(40’ - 60’) Four Bears Bridge : 10 Segments (100’) e rec ted in 1 day maximum Entire 316’ s pan in 9 days
FIGG
Four Bears Bridge Ft. Berthold Indian Reservation,
North Dakota FIGG
Balanced Cantilever Erection
Segments Can Be Erected using: • Barge-mounted cranes • Ground based cranes • Beam and Winch on cantilever end • Overhead Gantry
FIGG
New I-35W Bridge Minneapolis, Minnesota Opened in Sept 2008
1,214’ long, 504’ Mainspan FIGG
Presenter
Presentation Notes
This bridge utilizes an integral wearing surface.
Superstructure Precasting
1
Long Line Method
FIGG
Presenter
Presentation Notes
Long-line precasting for I35W project on closed main lanes of highway. Forms are set for entire span and segments are cast in sequential order. Segments are then separated and placed in storage.
New I-35W Bridge Minneapolis, Minnesota
120 segments placed in 47 days NTP to close of main span was 9 months
FIGG
Victory Bridge over Raritan River Sayreville, New Jersey
Opened in 2005 Twin 3,971’ Bridges
FIGG
Presenter
Presentation Notes
Typical approach span length = 150’ Main navigation span length = 440’ Bridge has an integral wearing surface. First of twin structure was opened 15 months after award of project. Second was opened 9 months later.
Rt. 36 Highlands Bridge New Jersey
McNary Bergeron
Opened in 2010 Twin 1600’ Bridges
Presenter
Presentation Notes
Precast construction was used from the footing up. Reason for precast construction: short construction season. Reason for segmental: Owner desire for durability in a marine environment.
Precast Span-By-Span Superstructure Construction
Susquehanna River Bridge Near Harrisburg, Pennsylvania
November 2004 - NTP Open in May 2007 - 5,910’ Twin Bridges
FIGG
Presenter
Presentation Notes
Typical span length = 150’ Bridge has an integral wearing surface. Concrete segmental was chosen for durability.
Casting Yard
Penn Turnpike Commission
Bridge
Precasting Susquehanna River Bridge
Near Harrisburg, Pennsylvania FIGG
57’ – 1 ¾”
6’ 12’ 36’
8’- 8”
Typical Segment - Susquehanna
Maximum Length: 13 Feet Maximum Weight: 104 Tons
FIGG
Precasting – Susquehanna
1040 – Total Segments (958 Typical, 82 Pier)
3 - Typical Casting Cells
1 - Specialty Casting Cell
FIGG
Precasting – Susquehanna Casting Bed
Core Form – easily inserted and withdrawn
FIGG
Precasting – Susquehanna Casting Yard
Match Cast Segment Wet Cast Segment
FIGG
Presenter
Presentation Notes
Short Line Casting Method
Casting Bed Transverse PT in Deck FIGG
Presenter
Presentation Notes
The durability of the deck is greatly enhanced because the top slab is post-tensioned in 2 directions. Note the use of plastic ducts in the transverse direction.
Casting Yard Storage FIGG
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Presenter
Presentation Notes
Bridge was erected from above because the water depth limited the use of barges. Also, the bridge crosses a rail line.
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania
FIGG
Presenter
Presentation Notes
Left photo: Epoxy is applied to both segment faces to seal the joint from moisture intrusion. Right photo: Each span has 2 closure pours.
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Presenter
Presentation Notes
Post-Tensioning Layout: Main tendons are external to the box. Note blisters used for temporary post-tensioning. Also, extra openings are provided for future post-tensioning, if needed. Utilities are contained on the inside of the box.
Superstructure Erection Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Presenter
Presentation Notes
Post-tensioning at pier. Note galvanized pipes for continuity tendons. Also, extra bearing plate for future PT.
Erected Rate - 3 Days Per Span
Susquehanna River Bridge Near Harrisburg, Pennsylvania
FIGG
Susquehanna River Bridge Near Harrisburg, Pennsylvania FIGG
Project remains as record holder for span-by-span erection.
Selmon Expressway Tampa, Florida Opened July 2006
FIGG
Presenter
Presentation Notes
Typical span length = 142’ Maximum span = 156’ Maximum rate of erection was 2400 LF in a month.
Selmon Expressway Tampa, Florida
“Feeling: George Jetson. For real. By the time I’m at my destination, it’s been 12 minutes suburb to city. They charge a dollar for toll. It should cost two.” Ben Montgomery, Reporter, St. Petersburg Times, July 19, 2006 (opening day)
“It’s probably the best thing that’s ever happened here... There’s no way I’d get there as fast as I do without it.” LaSchael Parks, Commuter, Tampa Tribune, July 16, 2007 (1 year after opening)
FIGG
Presenter
Presentation Notes
Reversible lanes provide additional capacity during commutes in and out of city.
Span-by-Span Erection
Segments Can Be Erected using:
• Under Slung Truss
• Overhead Gantry
Segment Delivery can be from above
or below.
FIGG
Precast Segmental Substructures
Victory Bridge over Raritan River
Sayreville, New Jersey Opened in 2005 Twin 3,971’ Bridges
FIGG
Presenter
Presentation Notes
Precast piers were used.
Precast Substructure First segment cast 6 weeks after NTP
Victory Bridge over Raritan River Sayreville, New Jersey
FIGG
Presenter
Presentation Notes
Left photo: Prefabrication of reinforcement
Victory Bridge over Raritan River
Sayreville, New Jersey Precast Substructure
FIGG
Presenter
Presentation Notes
Short line casting in vertical direction
Victory Bridge over Raritan River
Sayreville, New Jersey Typical Precast Pier Details
FIGG
Presenter
Presentation Notes
Details of looped tendons.
Victory Bridge over Raritan River Sayreville, New Jersey
Precast Pier Erection
FIGG
Presenter
Presentation Notes
Right photo: Starter segment positioned and grouted in correct alignment.
Victory Bridge over Raritan River Sayreville, New Jersey
Precast Pier Erection
FIGG
Victory Bridge over Raritan River Sayreville, New Jersey
Precast Pier Erection
FIGG
Presenter
Presentation Notes
Epoxy is applied to segment faces as a seal. Temporary post-tensioning is then stressed to squeeze out excess epoxy.
Victory Bridge over Raritan River Sayreville, New Jersey
Precast Pier Erection
FIGG
Presenter
Presentation Notes
Pier cap is placed, PT installed and tendons stressed to complete erection.
Completed Precast Piers 100’ tall piers erected in one day
FIGG
Rt. 36 Highlands Bridge New Jersey Precast Cofferdam
McNary Bergeron
Presenter
Presentation Notes
Casting location for precast cofferdams.
Rt. 36 Highlands Bridge New Jersey Precast Cofferdam
McNary Bergeron
Presenter
Presentation Notes
Left photo: reinforcing steel is installed and concrete placed in precast shell. Right photo: Precast pier segments installed.
Pier Table Erection McNary Bergeron
Precast Pier Shells
Presenter
Presentation Notes
The use of precast shell pier tables reduce hauling weight and provide an integral connection between the column and superstructure – very important in seismic locations.
Precast Pier Shells
McNary Bergeron
Pier Table Erection
Connections
PTI / ASBI Grouted Post-Tensioning Specifications
Presenter
Presentation Notes
Post-Tensioning is used for many ABC applications. PTI and ASBI have developed specifications for grouted post-tensioning.
• Reduced Construction Time • Environmental Protection • Maintain Traffic • Provide Aesthetics • Local Labor and Materials • Quality Control • Minimum Maintenance • Reduced Cost
FIGG
Precast Concrete Segmental Bridges Advantages:
142 Cimarron Park Loop, Suite F Buda, TX 78610-2837