Othmar Ammann Research Paper

Bridges have been used for thousands of years, beginning with natural formations, such as huge rock arches (Appendix A). The first bridges made by humans were most likely simple spans of wooden tree trunks laid across streams, or planks, such as rafts tied together (Gascoigne, 2001). These simple designs evolved over time, as new materials became available, to form the hundreds of bridges we use today. Some basic bridge designs include truss, arch, beam and suspension bridges. The most basic of these is the beam bridge (Appendix B1), which consists of a deck, spanning a relatively short distance, that is held up by a pair of abutments (vertical supports at either end). When weight is placed on

The report debates the Tacoma narrows bridge failure and the different theories of how it came about, using information about what type of bridge it is and the forces acting on it before and during the collapse. It also discusses ways in which the failure could have been avoided, from changes in the design to modifications to the bridge after its construction.

Suspension bridges were important before 1940 and are still important today. Major cities such as San Francisco, and Manhattan both have a suspension bridge. Suspension bridges are,” a bridge having a deck suspended from cables anchored at their extremities and usually raised on towers” (dictionary.com). Due to the fact that suspension bridges are not completely supported throughout the length of the bridge, past bridges were unsafe. For example, the Tacoma Narrows Bridge was a suspension bridge opened on July 1st, 1940 (Mark Ketchum). This bridge marked a huge point in suspension bridge safety and engineering, because in collapsed approximately four months after it was opened (Parsons). The collapse caused such a shock, that suspension

Pittsburgh is called the City of Bridges because it has 446 of them. The Smithfield Street Bridge is the oldest extant bridges. It was built from 1881 to 1883. It was not the first bridge to built in that spot. The first bridge to built there was Pittsburgh first bridge, a wooden bridge designed by Lewis Wernwag. That bridge was destroyed in the Great Fire. John Roebling’s suspension bridge was built next. The bridge was destroyed a year later due to stability. Then there are the “Three Sisters” bridges. Vernon Covell and his group of engineers plus an architect by the name Stanley Roush designed and built the

Yarden: While creating our bridge our initial plans were much different than what our final product was. The more we worried about the strength of the bridge, the less time we had. We started off with the idea to have a truss bridge made of wood and cardboard. As shown here, (show picture from journal entry), but as the project progressed our ideas continued to change.

There are many differences between our bridge and other bridges. One being location. Another one being that thing that was sacrificed for it. Another one being cost. Also another difference would be weight and capacity, and the size or length.

Stretching across the San Francisco Bay stands the world famous Golden Gate Bridge. The bridge is located in one of nature’s most beautiful settings, spanning the mile-wide bay from Fort Point in San Francisco to the Marin County Shore. Joseph Strauss, specializing in bridge building, was the leader of the construction of the Golden Gate Bridge. The start of construction began on January 5, 1993 and, after four years, was completed on April 27, 1997. The bridge was needed to be built because of the growing population after the California Gold Rush. The bridge was a difficult task for engineers and is now an inspiration. The Golden Gate Bridge is one of the largest suspension bridges and is well known around the world. The Golden Gate

In 1989, an earthquake caused the top deck of the bridge to collapse. This has raised concern in recent years in the case of a large scale earthquake. During an inspection in September of 2009, a 1.5 inch crack was found in a structural truss called an eyebar. The system of the truss is meant to distribute report will describe the tensile load from the weight of the bridge over 4 eyebars. One of them being broken, this same load was now distributed between only 3 eyebars. Because these eyebars were not designed to carry extra load, it became crucially important to repair the eyebar as soon as possible. However, because the bridge is so old, its mechanisms were more complex than what would be designed now in the current day. The engineering company C.C. Myers was contracted to do the repair. C.C Myers decided to repair the eyebar by welding a crossbar to the saddles which had been placed on each end of the broken eyebar (Alfrey, 2010). Four tie rods were then bolted to distribute the tensile load (Reid, 2010). This repair was completed in only 70 hours (Carlsen,

The Brooklyn Bridge, designed by German immigrant John Augustus Roebling. The bridge is known as the first hybrid steel- wire suspension bridge. It is one of the superb, oldest and longest bridges ever built in the world at the time it opened, spanning 1825m across east river connecting the Boroughs of Manhattan and Brooklyn in NY City. The most noticeable feature of the bridge is the two excessive towers, the 99-meter limestone granite towers overlook everything in view. The Brooklyn bridge was named “The eight wonders of the world” because of its iconic towers and length which have never seen before.

The man who drew the designs for the bridge was John Low Waddell. The people of Duluth were eager to build the lift bridge, which would have been about 130 feet wide. However, the War Department declined the design that John Waddell made, and the project was canceled before it could be built. Waddell's design went on to be built in Chicago. New plans were later drawn up for a structure that would bring people from one side to the other. This type of bridge was first demonstrated in Bilbao's Vizcaya Bridge in 1893. The Lift Bridge was then finally completed in 1905. After the history is learned the structure is very important as well to know. The height of the Lift Bridge is 180 feet when completely raised and the length is 386 feet and weighs approximately 900 tons. The bridge is very similar to the only other one of its kind in the world, which is in Rouen, France. The last and most important thing that

I enjoyed this project because it let us build, design, and test a bridge. It was a very hands-on project that required an excessive amount of thinking. There was a lot of measuring, cutting, designing, rethinking, testing, retesting, gluing, and re-gluing. There was a lot of thought behind building a strong and sturdy bridge. If I learned anything from this project it’s that architects and construction workers have a really complex job.

The Golden Gate Bridge is a modern marvel. It is amazing that Joseph B. Strauss was even able to create such a long bridge. There is no doubt that there were hardships along the way, but in the end, something great was

The Tacoma Narrows Bridge is perhaps the most notorious failure in the world of engineering. It collapsed on November 7, 1940 just months after its opening on July 1, 1940. It was designed by Leon Moisseiff and at its time it was the third largest suspension bridge in the world with a center span of over half a mile long. The bridge was very narrow and sleek giving it a look of grace, but this design made it very flexible in the wind. Nicknamed the "Galloping Gertie," because of its undulating behavior, the Tacoma Narrows Bridge drew the attention of motorists seeking a cheap thrill. Drivers felt that they were driving on a roller coaster, as they would disappear from sight in the trough of

No design is perfect. The Oakland Bay Bridge consisted of two eight-mile long, suspension bridges. C. H. Purcell first built it in the 1930’s. According to Britannica Online, he originally had structural issues with the sinking to bedrock in the central anchorage. When repairing the bridge after Loma Prieta, the challenge was making it more seismically sound. The West Span of the bridge held up due to its suspension design. This led to the West Span being more flexible than the East. Bridges must have a certain level of flexibility, but not so flexible that extreme conditions would create another disaster such as the Tacoma Narrows Bridge Collapse of 1940. The West side of the bridge was mostly in tension when the earthquake hit. Allowing the bridge to absorb forces and create equal and opposite forces of its own kept the West side of the bridge intact. However, the stiffness of the East Span of the bridge was too stiff to handle the brute force of the Loma Prieta earthquake. Having flexibility in a design allows for the bridge to react to outside forces. Being too rigid would give necessary allowance for certain

iii. The designing engineers should take all kinds of mistreat which can be collapsed the bridge. Therefore, they should imagine all those kinds of mistreat in the design processes.