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

Bridge Types Factors to Consider in Selecting Bridge Type • Geography • Geography Geography Geography – Gorge – Gorge – River – River – Falls – Falls – Falls – Falls • Loading • Loading – Vertical load from freight trains – Vertical load from freight trains – Longitudinal load from braking and traction of – Longitudinal load from braking and traction of L L it di it di l l l l d f d f b b ki ki d t d t ti ti f f trains trains • Aesthetics • Aesthetics – Unobtrusive to view – Unobtrusive to view – Visually pleasing – Visually pleasing

Bridge Types • Trestle • Trestle Trestle Trestle – Short spans supported by frames – Short spans supported by frames – Commonly used by railroad in 19 th and early 20 th – Commonly used by railroad in 19 th and early 20 th centuries centuries – Constructed of wrought iron, steel, or timber – 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 p pp pp y y • Steel Construction • Steel Construction

Bridge Types • Truss • Truss Tr ss Tr ss – System of straight, connected elements used to – System of straight, connected elements used to resist load resist load – Commonly seen as through truss or deck truss – Commonly seen as through truss or deck truss – Popular in 19 th and early 20 th centuries – Popular in 19 th and early 20 th centuries – Constructed of wrought iron, steel, or timber – 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 p • One Pier at Mid-Span • One Pier at Mid-Span • Steel Construction • Steel Construction

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

Bridge Types Proposed Arch Bridge • Spandrel-Braced Arch • Spandrel-Braced Arch p p • Abutments on Gorge Walls • Abutments on Gorge Walls • Steel Construction • Steel Construction

Bridge Types • Do you have any questions or • Do you have any questions or comments on the bridge types comments on the bridge types comments on the bridge types comments on the bridge types selected for consideration? selected for consideration?