Span Length

30′ 34′ 38′ 42′ 46′ 50′ 54′ Span Length TD27 x 3'-11 3/4" 30′ - 52′ TD27 x 4'-8" 30′ - 52′ TD27 x 4'-9 1/4" 30′ - 52′ TD27 x 5'-4" 30′ - 52′ TD27 x 5'-7 1/4" 30′ - 52′ TD27 x 5'-11 3/4" 30′ - 52′

Section Properties (gross)

HL-93 vehicle load, 52 ft. max. span (max. span is governed by handling.  U-80 vehicle load, 46 ft. max span. Alternate loading or longer spans may be acceptable with engineer review.

Product Name Depth (in) Area (in2) Yb (in4) Ixx (in4) Iyy (in4) PLF @ 165
TD27 x 3'-11 3/4" 27" 680 16.38 42149 147283 781
TD27 x 4'-8" 27" 730 16.91 44969 178431 838
TD27 x 4'-9 1/4" 27" 737 16.98 45364 184075 846
TD27 x 5'-4" 27" 787 17.35 47374 219192 904
TD27 x 5'-7 1/4" 27" 797 17.51 48272 239077 915
TD27 x 5'-11 3/4" 27" 824 17.73 49449 270057 946

Product Information

Typical Tri-Deck height is set at 2′-3″ with a standard 6″ thick top flange adjustable in width from 48″ to 84″. The top flange can be thickened to accommodate design requirements, however, reducing the stem height is difficult and not cost effective.

Standard Design Options

  • Integral Precast Curbs
  • Utility inserts
  • Air Entrained Decks
  • Bolts or Sleeves for Guard Rail Post Connection
  • Precast End Diaphragms
Technical drawing of a T-shaped metal component with three supporting legs and detailed dimensional specifications. Workers guide a concrete bridge deck into place during construction of the Tri-Deck over a rocky stream. Concrete tri-deck structure under construction with a crane lifting a large beam between thick support pillars. Underside of a precast concrete bridge deck showing support beams and embossed text reading

Need More Info?

We Are Here to Help

 

Have a question, need a budget or detailed schedule?  Knife River sales team is ready to discuss precast solutions for your project.  Reach out to our staff below :

A smiling bearded man in a black polo shirt with the Knife River logo on the chest.

Andy Roberts

Outside Sales, ID & MT

phone

509.904.8610
Portrait of Nikolaus Mixon, a bald man with glasses and a beard wearing a dark polo shirt with a Knife River logo.

Nikolaus Mixon

Outside Sales, OR & CA

phone

541.257.7412
Smiling man with a shaved head wearing a black Knife River polo shirt, likely a team member on the Our Team page.

Alex Sari

Outside Sales, WA & AK

phone

(509) 992-5614

 linkedin

LinkedIn

Product Family

See featured product related to Tri-Deck assemblies

All Products

AASHTO Girder

AASHTO sections are typically used for railroad, or other private entity, bridge construction when a standard wide flange (WF) girder section does not meet the project design criteria.  The top flange of AASHTO shaped girders is not as wide as standa...

View Product
Black dumbbell icon on white background

Box Beam

Box Beams are typically used for 80′-118′ bridge spans. The design allows for a typical 4′ width section to include integral voids which reduce the product weight and are often used when box depth and speed of construction are part ...

View Product
A black rectangular frame with a white cutout center, resembling a SIM card tray or photo frame.

Bridge Substructure

Accelerated Bridge Construction utilizes precast bridge substructure products. Total precast abutments, bent caps, pile caps and wingwalls offer many advantages. They can be precast to precise specifications of the design in a plant controlled settin...

View Product
Tapered single-cell box girder cross section showing the narrowed lower portion connecting to the pier.

Bulb I

The Bulb I (BI51, BI63 and BI75) is a less commonly used ODOT standard girder for medium to long length span bridges. It utilizes the BT section with the deck blocked in to achieve difficult site requirements such as heavy super elevations and vertic...

View Product
A black I-beam cross-section shape on a white background, representing a structural steel beam used in construction.

Bulb T

The Oregon Bulb-Tee (BT) girder is the preferred choice for most Oregon medium to long span bridges requiring a CIP deck. Bulb Tee precast/prestressed girders are typically used in spans from 60-185′ with significant loading.

View Product
Bold black uppercase serif letterform T on a white background.

Deck Bulb Tee

Deck Bulb Tee Girders combine a precast deck with the traditional I-Girder design. This design offers the advantage of an immediate driving surface, or alternatively, a roughened surface that allows for the addition of a secondary overlay or a Cast-I...

View Product
Deck bulb tee: a steel structural component with a top flange, tapered stem, and bulb-shaped foot.

Tri-Deck

Tri-Deck girders are an adjustable top flange width, multi-stemmed unit designed for full deck use. Tri-Deck bridges are typically used for bridge spans from 30′-52′ which require a longer span and lower profile section. Typically Tri-Dec...

View Product
Tri-Deck structure with three vertical supports beneath a horizontal beam.

Voided-Solid Slabs

Voided Slabs are typically used for 15-85′ bridge spans but can be used in building applications where significant design loads are required. Voided slab design allows for a typical 4′ width slab to include integral voids which reduce the...

View Product
Black slab with two circular voids illustrating a voided-solid slab design.

Projects

Commercial

Industrial

Institutional

Residential

Transportation