Bridge Types Factors to Consider in Selecting Bridge Type - - PowerPoint PPT Presentation

Bridge Types

• Geography
• Geography

Factors to Consider in Selecting Bridge Type Geography

– Gorge – River – Falls

Geography

– Gorge – River – Falls – Falls

• Loading

– Vertical load from freight trains L it di l l d f b ki d t ti f – Falls

• Loading

– Vertical load from freight trains L it di l l d f b ki d t ti f – Longitudinal load from braking and traction of trains

• Aesthetics

– Longitudinal load from braking and traction of trains

• Aesthetics

– Unobtrusive to view – Visually pleasing – Unobtrusive to view – Visually pleasing

Bridge Types

Trestle Trestle

• Trestle

– Short spans supported by frames – Commonly used by railroad in 19th and early 20th

• Trestle

– Short spans supported by frames – Commonly used by railroad in 19th and early 20th centuries – Constructed of wrought iron, steel, or timber centuries – Constructed of wrought iron, steel, or timber

Bridge Types

Proposed Trestle Bridge

• Girder Spans Supported by Tower Bents
• Girder Spans Supported by Tower Bents

p pp y

• Steel Construction

p pp y

• Steel Construction

Bridge Types

Tr ss Tr ss

• Truss

– System of straight, connected elements used to resist load

• Truss

– System of straight, connected elements used to resist load – Commonly seen as through truss or deck truss – Popular in 19th and early 20th centuries – Constructed of wrought iron, steel, or timber – Commonly seen as through truss or deck truss – Popular in 19th and early 20th centuries – Constructed of wrought iron, steel, or timber g , , g , ,

Bridge Types

Proposed Truss Bridge

• Two-Span Continuous Deck Truss
• Two-Span Continuous Deck Truss

p

• One Pier at Mid-Span
• Steel Construction

p

• One Pier at Mid-Span
• Steel Construction

Bridge Types

Arch Arch

• Arch

– Transfers load through arched element as horizontal thrust at abutments

• Arch

– Transfers load through arched element as horizontal thrust at abutments – Oldest bridge form – Constructed from stone, concrete, or steel – Oldest bridge form – Constructed from stone, concrete, or steel

Bridge Types

Proposed Arch Bridge

• Spandrel-Braced Arch
• Spandrel-Braced Arch

p

• Abutments on Gorge Walls
• Steel Construction

p

• Abutments on Gorge Walls
• Steel Construction

Bridge Types

• Do you have any questions or

comments on the bridge types

• Do you have any questions or

comments on the bridge types comments on the bridge types selected for consideration? comments on the bridge types selected for consideration?