The Natchez Trace bridge how was it built?
113757
One of the most revolutionary arch bridges in recent years is the Natchez Trace Bridge in Franklin, Tennessee, which was opened to traffic in 1994. It's the first American arch bridge to be constructed from segments of pre-cast concrete, a highly economical material. Two graceful arches support the roadway above. Usually arch bridges employ vertical supports called "spandrels" to distribute the weight of the roadway to the arch below, but the Natchez Trace Bridge was designed without spandrels to create a more open and aesthetically pleasing appearance. As a result, most of the live load is resting on the crowns of the two arches, which have been slightly flattened to better carry it. Already the winner of many awards, the bridge is expected to influence bridge design for years to come.
541708
NASA took a photo of the Palk Strait between India and Sri Lanka that shows a series of shoals lying in the water between two points of land.  It the shoals were above water, they would connect the two points of land and form a bridge between India and Sri Lanka.\n\nSome have claimed that this is the bridge that Rama commanded to be built in the Hindu epic Ramayana.  A few archaeologists claim to have found evidence suggesting that the bridge is man-made.\n\nNASA has distanced itself from such claims with the following quote:\n\n"The images [...] may be ours, but their interpretation is certainly not ours. [...] Remote sensing images or photographs from orbit cannot provide direct information about the origin or age of a chain of islands, and certainly cannot determine whether humans were involved in producing any of the patterns seen."
372305
http://www.mbr-pwrc.usgs.gov/bbs/anim/h3520.html
275438
Rennie.  \nHis London Bridge granite facings were shipped to Lake Havasu City, Arizona, and built into a new bridge there in 1971. \nThe great breakwater at Plymouth England make it the one of the best harbours in the world for close to 200 years.\nIt took a while to find the name :)
394220
Build a bridge and get over it
5622
None.. It was Noah's Ark
853367
Tynset Bridge \nThe Tynset Bridge crosses the river Glomma in Hedmark County about 400 km north of Oslo. With its 70 metres span, Tynset Bridge is the longest spanning timber bridge in the world designed for full traffic loading. The bridge is in the national road network and has to carry lorries up to 60 tons.
587676
Go to http://www.bridges.com/us/home.html
70111
James Hoban designed the whitehouse and it began contruction in 1792 by stonemasons from Scotland.  He won the contract, and even Thomas Jefferson, the third president, submitted drawings for the new building.  All materials used in building all came from the states, the stones from Stafford County - Virginia, and the wood from North Carolina and Virgina.
519638
The Oregon City Bridge is a steel arch bridge that spans the Willamette River between Oregon City and West Linn, Oregon. It was built and is owned by the Oregon Department of Transportation (ODOT) as part of Oregon Highway 43 and is the southernmost Willamette bridge in the Portland metropolitan area.\n\nThe bridge is 745 ft. (227 m) in length and 28 ft. (8½ m) wide with a 360 ft. (110 m) long main span that provides 49 ft. (15 m) of vertical clearance at low river levels. The narrow width causes problems for the two bus lines and other big vehicles that cross it, often times requiring traffic going in the other direction to stop. In addition, it is the only bridge in Oregon to be encased in gunite, which protects it from corrosion due to the sulfur dioxide emissions from paper mills south of the bridge. The concrete look was favored by bridge designer Conde McCullough, designer of 500 Oregon bridges. His signature detailing is evident in the obelisk pylons with sconced light fixtures, ornate railings, and Art Deco piers.\n\nThe Oregon City Bridge is just downstream from the 40 ft. tall Willamette Falls and the Willamette Falls Locks, the oldest navigational locks in the United States. Just upstream is the Abernethy Bridge and Interstate 205.\n\nThe bridge was built as a replacement of a pedestrian suspension bridge constructed in 1888. It was opened on December 28, 1922 at a cost of $300,000.\n\nThe piers were designed to accommodate public restrooms: decks widen at the piers to provide room for the stairways that descend to the restrooms. Repeated vandalism led in 1937 to the closure of the restrooms.\n\nAs of 2000 it carried 12,800 vehicles per day, which represents only a 40% growth in traffic since 1953, when a public debate was held about building a parallel bridge next to the existing bridge. While the Oregon City Bridge did not get twinned, the Abernethy Bridge opened in 1970 and has since become the major route through the area.
622351
to get the foundations over water, there are several ways to get the foundation for the bridge set up over the water.  one way is to float out a platform that is not unlike an oil derrick.  from there 'piles'(columns made out of concrete or steel)are driven down into the ocean floor and a foundation is rested and secured and built on it until you get to the top.  \n\nthe other way is (in shallower water) to build a 'coffer dam'  this is a temporary structure that you would build around the place that you want the foudmnation for the bridge in the water.  you put the dam around the area, pump out the water, and then build a foundation as you normally would, or even place piles like the example from above.
228519
A civil engineer can give you a better answer to this question than I, a Mechanical Engineer, but basically it comes down to what kind of bridge can be built based on its location.\n\nFor example, you're going to build a different kind of bridge over a river than you will over the San Fransisco Bay, simply because their size, depth, and needs are different.  In addition, the builders need to take the local weather patterns into account when building the bridge, because areas of high wind velocity are not going to want bridges with particular characteristics (a popular video to show in Engineering classes is the destruction of the Tacoma Narrows bridge in 1940 caused by harmonic oscillation arising from vibrations caused by high wind speed).  Location simply determines function, which then determines load.\n\nThe question then becomes tantamount to how do different bridge types support loads differently, which becomes a basic engineering question: the advantages of a suspension bridge over a truss or rigid frame bridge, etc., and the related difficulties of building each in particular areas.\n\nAreas of high silt or soft mud aren't going to want bridges that require alot of pilings, because it invites disaster - it provides more possible points of failure.  Instead, you would want a bridge with one or two heavy pilings that are capable of holding a huge load, like your typical suspension bridge.  With a suspension bridge, a snapped cable is not fatal to the function of the bridge, because the supportable load changes almost imperceptably.\n\n(I leave as an exercise to the reader to take a typical bridge span of 1000 feet, calculate the integral of the Moment over the length of the bridge [to give you the sheer force], and divide that by the number of cables - the load each cable holds is very small).\n\nThe attached link, while intended to be an educational game, gives you a basic idea of what I'm talking about.
600108
New Orleans.... Looking for help... experience in levee wall building and maintaining preferred.  \n\nBring a bullet proof vest.
423917
I'd say the triangle; that is why most bridges are built with a "Triangle Truss." It makes the bridge more stable.
1082644
The Bridges of Madison County.
245673
It was designed by chief architect Bruce Graham and structural Engineer Fazlur Khan of Skidmore, Owings, & Merrill.\n\nWas built by I guess Sears and the city of Chicago.
795507
Garndiffaith viaduct, constructed by John Gardner 1878\n\nCheck out the link below.\nIt was the best i could find .\n\nHave a nice day ...\n☺☺☺