Exhibit Area 1
(Plaza area)
Welcome Sign [main directory]
How the Bridge Spans the Golden Gate
Bridge Aesthetics - Art Deco on a Grand Scale
Tall and Strong - The Bridge Towers
Steel, Fog, Salt, Rust, and Paint

Exhibit Area 2
(near flagpole)
How the Bridge Vibrates
Foghorns

Exhibit Area 3
(West side of Bridge near underpass)
Historic Preservation: Lattice Strut Retrofit
Historic Preservation: Isolator Seismic Retrofit

Exhibit Area 4
(inside Battery area)
History: Design and Construction of the Bridge
Suspension Cable Tension vs. Tower Height
Battery Lancaster - Defending the Golden Gate

Exhibit Area 5
(along bike path to lower parking lot)
Bridge Deck Aerodynamics
Bridge Deck Torsional Resistance Retrofit
Wind Speed and Wind Pressure

Exhibit Area 6
(near Pavillion)
LIFETILES: animated construction of the Bridge
Braille / Tactile Model of the Bridge



Project Partners

GGBHTD
Golden Gate Bridge,
Highway and Transporation District



CUREE

Consortium of Universities for Research
in Earthquake Engineering

Main Menu : Exhibit Area 1

How the Bridge Spans the Golden Gate

ANATOMY OF A SUSPENSION BRIDGE

1. Deck Trusses

Look at the trusses that extend along the length of the Bridge. The weight of the roadway and sidewalk structure, and of the cars, pedestrians, and bicyclists, is supported by the deck trusses. The diagonal struts outline the basic structural unit of a truss, the triangle, which is inherently strong and stiff. However, the deck trusses are not strong enough to span all the way across the Golden Gate. They are held up every 50 feet (15 meters) by vertical steel suspender ropes.

2. Suspender Ropes

See the 500 vertical lines (steel suspender ropes) across the Bridge? They are the next step in the “load path”, which is the term that describes how the weight of the Bridge, including the weight of traffic, is transferred ultimately to the ground. The deck trusses hand off their load to the ropes, which pull that weight up to the curving main cables. The weight of the deck is suspended from the main cables by these suspender ropes, hence their name.

3. Main Cables

When you look at the tops of the two towers of the Bridge, you see where the two cables are supported. All the weight of the roadway and sidewalk deck structure, the traffic, the steel suspender ropes, and the self-weight of the curving main cables, is placed on the tops of the two towers by the cables.

4. Towers

What holds up the two main cables? When you wear a backpack, the straps pull the weight up to your shoulders, and then that load must travel a path down your body all the way through your legs to the ground. The poles that hold up a tent, or a tightrope walker at the circus, or a clothesline, must also carry the weight to the ground. In the Bridge, the towers carry all the gravity loads of the entire suspension structure, from one end to the other, down to the ground.

5. Foundations

The foundations are the final step in the load path. The forces carried down through the steel towers are resisted by the strength of the concrete foundations, which extend into bedrock. The pulling or tension forces in the cables are resisted by the massive concrete anchorages at both ends of the Bridge, and those anchorages are also embedded in bedrock. The loads of the Bridge flow through the foundations and reach the earth, completing the load path.


All images property of the Golden Gate Bridge, Highway and Transportation District (unless otherwise indicated).


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Last updated: 11.08.12