CE 1000: History of Structures - Exam 2
Mungstener
(NOT by Eiffel) - Looks like Garabit Viaduct - Pier into arch - Fixed support
Eads Brdige
- 510 ft - steel bridge
Ammann's Important Bridges
- Bayonne Bridge - George Washington Bridge - Triborough Bridge - Throgs Neck Bridge - Verrazzano Narrows Bridge - Bronx-Whitestone Bridge
Golden Gate Bridge advisory board members
- Charles Ellis - Leon Moissieff - Joseph Strauss - Othmar Ammann - Charles Derleth
Gustav Lindenthal
- Colleague influence on Othmar Ammann - Practical, politics
Garabit Viaduct
- Deck is above arch - Separate pier - Hinged support
Elastic Theory
- Deep decks - Rely on deck stiffness - Limited span / depth
Joseph Strauss
- Fires Ellis in 1931 - Gives him no credit
Gustav Eiffel
- Good designer and builder - Went to school for chemical engineering - Worked with railroad parts
Golden Gate Bridge designers
- Joseph Strauss - Charles Ellis - Leon Moissieff
GGB consultants
- Leon Moissieff - Othmar Ammann - Charles Derleth
Firth of Forth Bridge
- Longest spanning bridge at the time, also a railroad bridge (great achievement) - reaction going up = reactions going down - robust structure
Bayonne Bridge (1652 ft)
- Scientific: trussed arch - Social: raising the deck - Symbolic: Ammann's aesthetic
James Buchanan Eads
- Self educated - Made fortune in salvage - Designed diving bell (submarine)
Wilhelm Ritter
- Teacher influence on Othmar Ammann - Technical, aesthetic
Deflection Theory
- Thin decks - Rely on cable stiffness
Pia Maria Bridge
- Trussed arch - Main support at quarter points - Deck merges into top of arch
Eiffel's 3 important bridges
- Viaduct at Rouzat - Pia Maria Bridge - Garabit Viaduct
Collapse of Tacoma Narrows
- aeroelastic flutter - 42 mph winds
Charles Ellis
- complex math - complex loads - telegrams back & forth with Moissieff - NAS conference - "brains" behind design
Reinforced Concrete
- great in compression, not tension - steel reinforcement for tensile stresses
Joseph Strauss
- merely manager - frustrated with "all the time" it was taking Ellis to finalize design
Force
- taller towers --> smaller cable forces --> smaller cables - d = sag
Eiffel Tower
Air surrounding weighs more
Firth of Forth Bridge
Benjamin Baker
Construction of GGB
Cables: - wires --> strands --> cables, spinning cable wires, forming cable, cable bands & suspenders, maintenance
GGB secretary
Charles Ellis
Viaduct at Rouzat
First bridge from to reflect influence of wind
Eads Bridge significance
First significant steel bridge
Eiffel Tower
Idea was to take apart and take to Dijon
Eiffel Tower
Jacks to adjust orientation during construction
Eads Bridge
James Eads
GGB chief engineer
Joseph Strauss
Golden Gate Bridge
Maintenance: corrosion, painting, upgrades/enhancements
Garabit Viaduct
Mature work
Golden Gate Bridge
Not structural art, but beautiful
Clifford Paine
Replaces Charles Ellis
Eiffel Tower
Scientific: - Material = iron - Structure type = cantilever - Dominating force = wind
Washington Monument
Scientific: - Material = stone - Structure type = column - Dominating force = gravity
Gustav Eiffel
Scientific: bridge forms to resist wind
Firth of Forth Bridge
Scientific: horizontal cantilever Social: response to Firth of Tay collapse Symbolic: visual perspectives
Eads Bridge
Scientific: trussed arch Social: Chicago vs. St. Louis and the railroad Symbolic: hope for economic dominance
Effects of wind on long span bridges
Scientific: wind and self-excitation/flutter Social: science over history Symbolic: back to the future, new forms for bridge decks
Washington Monument
Social/symbolic: - End of American Revolution - Many pieces - One monument
Eiffel Tower
Social/symbolic: - End of French Revolution - Many pieces - One tower
Gustav Eiffel
Social: the Portuguese bridge competition
Firth of Forth Bridge forces
Structure system: - cantilevers with suspended middle span
Construction of GGB
Symbolic: - color: international orange - decoration: art deco facade - 75th anniversary
George Washington Bridge
Symbolic: - heavy stone towers (symbol of past) - thin deck (symbol of future)
Gustav Eiffel
Symbolic: beauty in simplicity and rational forms
Moment diagram
Tells you how much cumulative moment each slice of a structure has to resist without toppling over
Moment (M)
Tension/compression couple
Eads Bridge social aspect
To re-establish St. Louis as the dominant gateway to the west over Chicago
Construction of GGB
Towers: - starts with towers - south tower most challenging
Eiffel Tower
Trusses within trusses to create a hollow, lightweight form
Eiffel Tower
Was not supposed to be built
Pia Maria Bridge
Won design competition (by Eiffel)
The ends help with (Firth and Forth Bridge)
additional support
Bottom is in (Firth and Forth Bridge)
compression
Deflection Theory
heavier the span weight, greater the cable tension --> greater the cable tension, stiffer the span --> stiffer the span, less need for deck trusses
Mens arms are (Firth of Forth Bridge)
in tension
Defection Theory
span / depth
Mens arms represent (Firth and Forth Bridge)
steel limbs
Top is in (Firth and Forth Bridge)
tension
Diagonal sticks represent (Firth and Forth Bridge)
think steel tubes
Men in chairs represent (Firth and Forth Bridge)
towers from base to top
Stress
weight of structure (force) / footprint of tower (area)
