Segmental Concrete Bridge Technology

What is the Real Cost of a Segmental Bridge?

The actual cost of a segmental bridge can vary widely. Large projects (100-200 short spans) in favorable locations have been constructed for 40 $/square foot while other long, 3-span segmentals built in difficult-to-access sites cost 300 $/square foot.

Factors that affect cost are the same for segmentals as for other bridge types:

• Span Length: longer spans have higher per square foot costs.
• Project Size: economy of scale applies especially for segmental bridges: smaller projects are more expensive per square foot because of high start-up costs.
• Site Access: restrictions to haul vehicle and crane movements can increase cost.
• Regional Variance: geological conditions, indigenous concrete quality and local labor costs can dramatically affect cost.

For a more comprehensive listing of actual bridge costs, see the Library.

Other obscured, but still very real, costs incurred by the owner of a segmental bridge include:

• Design Fees: Segmental Bridges are non-standard and require specialized designers and software. Plan preparation is longer than for other bridge types because so little is routine.
• QA/QC: Segmental bridges require custom specifications. The AASHTO "Guide Specifications for Design and Construction of Segmental Concrete Bridges" contains basic construction specifications but these need to be tailored for the specific job and integrated with the owners existing bridge specifications. The owner will either need to train his own forces or hire specialists to perform inspections. Early segmental bridge projects frequently had large claims filed for incomplete plans and specifications.
• Continuing Engineering Services: The owner needs engineering expertise during the construction phase to approve shop drawings (contract plans seldom detail every individual segment with every bar length, drain inlet, electrical conduit etc.), evaluate design alterations that improve constructability and troubleshoot inevitable design and construction errors. This is frequently provided by the designer. Claims can mount for the unprepared owner who delays in responding to contractor inquiries.
• Longer Construction Time: Segmental bridge construction requires specialized formwork, falsework and construction equipment. These all delay the beginning of superstructure construction.