THE GOLDEN GATE BRIDGE
By Jamir Coker
WHAT IS IT?
•
The Golden Gate Bridge is a suspension bridge spanning the golden gate the opening of the San Francisco Bay into the Pacific Ocean.
• It was officially built in 1937, and took four years to build.
HISTORY
• There was a ferry used to cross the San Francisco Bay that began in the 1820’s. • Named the Golden Gate Ferry Company in 1867. • The proposal was finally an made in the late 1920’s San Francisco was the largest American city still served primarily by ferry boats
STRUCTURE
• The weight of the roadway is hung from two cables that pass through the two main towers and are fixed in concrete at each end. • Each cable is made of 27,572 strands of wire.
• There are 80,000 miles of wire in the main cables.
ISSUES
• More people die by suicide at the Golden Gate Bridge than at any other site in the world. • Most jumpers die from impact trauma on contact with the water. It is approximately 245 feet above the water • By 2005, this count exceeded 1,200 and new suicides were occurring about once every two weeks. • It was reported as the second most popular place to commit suicide behind the Aokigahara Forest in Japan.
ISSUES PT. 2
• The effect of earthquakes on structures led to a program to retrofit the Golden Gate to better resist seismic events. • The proximity of the bridge to the San Andreas fault places it at risk for a significant earthquake. • A $392 million program was initiated to improve the structure's ability to withstand such an event with only minimal damage.
WHAT ARE SEISMIC EVENTS
• Seismic events are occurrences in which energy is briefly released in the Earth's crust, resulting in a series of seismic waves which move through the crust. • In some cases, the energy can be intense enough that it is felt in the form of an earthquake • In other seismic events, the energy is so mild that it can only be identified with specialized equipment.
ECONOMICS
• In November 2006, the Golden Gate Bridge, Highway and Transportation District recommended a sponsorship program for the bridge to address its operating deficit. • It projected at $80 million over five years. The District promised that the proposal for the defecit in operation • In October 2007, the Board unanimously voted to discontinue the proposal and seek additional revenue through other means, most likely a toll increase.
HANDLING SUICIDAL PROBLEMS
• The bridge is fitted with suicide hotline telephones, and staff patrol the bridge in carts, looking for people who appear to be planning to jump. . • The bridge is now closed to pedestrians at night. • Cyclists are still permitted across at night, but can buzz themselves in and out through the remotely controlled security gates.
ABOUT THE BRIDGE
• In 1937, the Golden Gate Bridge had the longest suspension bridge main span in the world, at 4,200 feet. • Since 1964, its main span length has been surpassed by nine other bridges. • Longest main span in the US, after the Verrazano-Narrows Bridge in NYC.
REFERENCES
• ^ "Golden Gate Transportation District". • Goldengate.org. Retrieved June 20, 2010. ^ Golden Gate Bridge at Structurae ^ a b Denton, Harry et al. (2004) "Lonely Planet San Francisco" Lonely Planet, United States. 352 pp. • ISBN 1-74104-154-6 ^ http://www.dot.ca.gov/hq/traffops/saferesr/trafdata/truck2006final.pdf Annual Average Daily Truck Traffic on the California State Highway System, 2006, p.169 ^ "Golden Gate Bridge". Office of Historical Preservation, California State Parks. Retrieved 2012-10-08. • ^ "City of San Francisco Designated Landmarks". City of San Francisco. Retrieved 2012-10-21. ^ "American Society of Civil Engineers Seven Wonders". Asce.org. July 19, 2010. Retrieved August 30, 2010.