ODOT Structure Project Manager Training

Structure Types

Common Structure Types

• Pipe culverts– Includes reinforced concrete and

corrugated metal round pipes, reinforced concrete elliptical pipes, and corrugated steel and aluminum pipe arches

– Structural design criteria addressed in Location and Design Manual, Volume 3, Section 1008

Round Concrete Pipe

Round Corrugated Steel Pipe

Elliptical Concrete Pipe

Common Structure Types (cont’d)

• Box culverts– Includes precast reinforced concrete box

culverts, corrugated steel and aluminum box culverts, and corrugated steel long span culverts

– Not unusual to see concrete box culverts replace small, single span bridges

– Location and Design Manual, Volume 3, Section 1008 for design criteria

Precast Concrete Box Culvert

Precast Concrete Box Culvert

Common Structure Types (cont’d)

• Three sided culverts– Includes precast reinforced concrete flat-

topped culverts and precast reinforced concrete arch sections

– Flat-topped available from 14 to 34 ft. span– Arch available from 12 to 42 ft. span– Location and Design Manual, Volume 3,

Section 1008 for design criteria

Flat-Topped 3 Sided Culvert

Flat-Topped 3 Sided Culvert

Precast Reinforced Concrete Arch

Precast Reinforced Concrete Arch

Common Structure Types (cont’d)

• Bridges (Bridge Design Manual, Section 200)– Superstructures consisting of cast-in-place

concrete slabs, prestressed concrete box or I-Beams, and structural steel beams and welded plate girders

– Shallow abutments with spill-though earthslopes are preferred for stream crossings

– Pier type typically depends on what feature is being crossed by bridge

Cast in Place Slab with Capped Pile Piers

Concrete Box Beams with Cap and Column Piers and Drilled Shafts

Rolled Steel Beams with Cap and Column Piers

Welded Plate Girders with Single Column Piers

Factors Affecting Structure Type

• Economic considerations• Site constraints• Hydraulic requirements• Subsurface conditions• Maintenance of traffic• Construction time• Utilities (rare)

Economic Considerations

• General hierarchy of construction costs (least to most expensive)– Pipe culvert– Box culvert– Three sided culvert– Bridge

• Other factors (hydraulics, subsurface conditions, etc.) can outweigh general hierarchy

Site Constraints

Maintenance of Traffic

Limitations on Use of Common Structure Types

• Culverts – Material durability, minimum and maximum cover restrictions, subsurface conditions, structure skew relative to roadway, maintenance of traffic

• Bridge superstructures - Curved roadway alignment, structure skew relative to roadway, required span length, maintenance of traffic